Part 1: Exploration and Early Claims (1805–1840s)
In 1805–1806, the Lewis and Clark Expedition (Corps of Discovery) entered present-day Washington along the Snake and Columbia Rivers, reaching the Pacific and documenting the region and its Indigenous peoples. This strengthened U.S. claims. Earlier European exploration included Spanish, British, and Russian voyages along the coast. The fur trade expanded with posts by the North West Company, Hudson’s Bay Company, and American interests (e.g., John Jacob Astor’s Pacific Fur Company at Fort Astoria and Fort Okanogan around 1811). David Thompson navigated the full Columbia River.
The 1818 Treaty of Joint Occupation allowed shared U.S.-British control of the Oregon Country. The 1846 Oregon Treaty fixed the boundary at the 49th parallel, resolving the dispute peacefully. American settlement accelerated via the Oregon Trail in the 1840s.
Territorial Period (1848–1889)
Oregon
Territory was organized in 1848. Settlers north of the Columbia River
sought separate government due to distance from the capital. On March
2, 1853, Congress created Washington Territory (named for George
Washington), initially including present-day Washington plus parts of
Idaho and Montana. Olympia became the capital; Isaac Stevens served
as first governor and negotiated treaties with tribes (often
contentious, leading to conflicts in the 1850s).
Boundaries stabilized in 1863 when Idaho Territory was carved out. Growth accelerated with gold rushes, agriculture, logging, and especially the Northern Pacific Railroad’s arrival in the 1880s, which connected the territory to national markets and spurred population booms in Seattle, Spokane, and elsewhere. Anti-Chinese violence and labor tensions marked the era. Multiple statehood attempts failed earlier due to low population, political balances in Congress, and local reluctance over losing federal support.
Path to Statehood
The Omnibus Enabling Act
(signed February 22, 1889, by President Cleveland) authorized
Washington (along with the Dakotas and Montana) to draft a
constitution. A convention met in Olympia from July 4 to August 22,
1889. Voters ratified the constitution on October 1, 1889 (40,152 to
11,789). On November 11, 1889, President Benjamin Harrison proclaimed
Washington the 42nd state. Elisha P. Ferry became the first state
governor. Women’s suffrage and prohibition were rejected at the
time (suffrage later passed in 1910).
Politics from Statehood to the Present
Early decades featured Republican dominance, reflecting business, railroad, and development interests. Populist and Progressive movements arose in response to railroad monopolies and economic inequality; John Rogers (Populist/Democrat) won the governorship in 1896. The Progressive Era brought reforms such as the initiative and referendum (1912).
The Great Depression shifted politics leftward. New Deal programs and strong labor (especially in Seattle and shipyards) boosted Democrats. Post-World War II saw alternating control, with notable Republican governors like Daniel Evans (1965–1977) and John Spellman (1981–1985). Since the 1980s–1990s, Democrats have dominated statewide offices, holding a long streak of Democratic governors (Booth Gardner onward, continuing into the present with Bob Ferguson as of 2025). The state leans strongly Democratic in presidential elections since 1988 and maintains Democratic legislative majorities in recent decades, though eastern Washington remains more conservative. Key modern issues include technology/economy (Microsoft, Boeing, Amazon), environment, housing, and social policy.
Shift in Social Programs: From Private to State/Public Control
Before the 1930s, relief relied heavily on private charities, churches, mutual-aid societies, and limited local public poor relief (often sparse and stigmatized). Organizations like Seattle’s Bureau of Associated Charities/Social Welfare League coordinated private efforts.
The Great Depression overwhelmed private systems. Federal New Deal programs (FERA, CWA, WPA) and state responses (Washington Emergency Relief Administration) shifted primary responsibility to government. Federal rules increasingly required public (not private) administration of relief funds. Unemployment insurance began in Washington in the late 1930s following the Social Security Act of 1935. Workers’ compensation and other protections expanded earlier or around this period.
Postwar decades brought further public expansion: Medicaid (1965, later rebranded Apple Health with major expansion under the ACA in 2014), welfare-to-work programs (WorkFirst after 1990s federal reforms), and broader health/social services under DSHS and the Health Care Authority. Private nonprofits continued specialized roles (family counseling, etc.) but government became the dominant funder and provider of basic safety-net programs.
Recent expansions include Paid Family and Medical Leave (benefits starting 2020) and the WA Cares Fund (long-term care insurance, enacted 2019, with payroll contributions and benefits rolling out in the 2020s)—both public, mandatory social-insurance models rather than purely private or voluntary.
Part 2: Tax Rates and Structure Over Time
From territory through the early statehood period into the 1930s, property tax was the primary revenue source for state and local government.
The Great Depression and property-tax limits (including the 40-mill limit) prompted the 1935 Revenue Act, which introduced the retail sales (consumption) tax, and the business and occupation (B&O) tax (a gross-receipts tax) as major alternatives. This shifted the system toward consumption and business activity taxes. Washington has never successfully enacted a broad personal income tax (voters approved one in 1932, but the state Supreme Court struck it down in 1933 as violating uniformity rules; later attempts failed).
Sales tax: Introduced in the mid-1930s; the state rate has been increased several times, with the last major state-rate increase in 1983. Combined state + local rates today typically range from about 7% to over 10% depending on locality (local options for transit, criminal justice, etc., have added layers).
B&O tax: Rates have varied by classification (retailing, wholesaling, services, etc.) and been adjusted repeatedly since 1935 (examples include increases via surtaxes in the mid-20th century and more recent tiering/surcharges for higher-revenue businesses and specific sectors).
Property tax: Remains important, especially for schools and local services, but subject to strict limits (e.g., 1% annual levy growth limit under Initiative 747 and related laws, with exceptions for new construction and voter-approved lids). Rates (expressed per $1,000 of assessed value) fluctuate with property values and budgets.
Other taxes (real estate excise, public utility, fuel, etc.) have also evolved.
Overall, the tax burden has grown with the expansion of government services, infrastructure, education, and social programs, though Washington’s structure remains unusual among states for its heavy reliance on sales and B&O taxes rather than personal income taxes. Revenues have funded the shift from limited territorial government to a modern state with extensive public services.
This is a high-level overview drawing on historical records, timelines, and official sources.
The 2026 “Millionaires’ Tax” (Personal Income Tax on High Earners)
In March 2026 the Democratic-controlled Legislature passed ESSB 6346 (the Millionaires’ Tax), which Governor Bob Ferguson signed into law on March 30, 2026. It is Washington’s first broad personal income tax. The tax imposes a flat 9.9% rate on an individual’s Washington taxable income above a $1 million standard deduction (indexed for inflation). For married couples or registered domestic partners the combined deduction is capped at $1 million. It applies only to the portion of income exceeding that threshold; income at or below $1 million is not taxed under this measure.
Key details:
Takes effect for tax years beginning on or after January 1, 2028 (first returns and payments due in 2029).
Starts from federal adjusted gross income with state-specific modifications.
Estimated to affect roughly 20,000–25,000 households (less than 0.5% of taxpayers) and raise approximately $3–3.5 billion per year once fully in effect.
Revenue is partly earmarked for tax relief measures (expanded Working Families Tax Credit, sales-tax exemptions on items such as diapers, small-business relief) and other state priorities including education and human services.
It coexists with the existing capital-gains excise tax (7% on long-term gains above an inflation-adjusted deduction, rising to a combined 9.9% on gains above $1 million).
As of mid-October 2026 the tax faces two immediate hurdles:
Initiative 645, which will appear on the November 3, 2026 ballot, seeks to repeal the tax and permanently prohibit state or local taxes on individual income.
Legal challenges are expected or underway, centered on the long-standing 1933 Washington Supreme Court precedent (Culliton v. Chase) that treated income as property and barred non-uniform (progressive) income taxes under the state constitution. Supporters hope the Court will distinguish or overturn that ruling; opponents argue the new tax is an unconstitutional income tax regardless of the “millionaires” label.
Expanding the Income Tax
Some Democratic
legislators have publicly indicated interest in eventually broadening
the tax. Statements have included support for lowering the threshold
(for example, to $250,000, sometimes called a “quarter-millionaires
tax”) at a lower rate, or making the tax more general as part of
broader tax reform. Governor Ferguson has pledged to veto any attempt
to lower the threshold below $1 million while he remains in office.
Opponents characterize the current law as a “Trojan horse” or
“camel’s nose under the tent,” arguing that once an income-tax
framework is established and survives legal and ballot challenges,
future legislatures will find it politically easier to expand the
base or raise rates. Proponents counter that the high threshold and
paired tax cuts make expansion unlikely in the near term and that the
measure simply makes the overall tax code less regressive.
Economic-growth considerations
High marginal
tax rates on top earners and high-growth returns can influence
location, investment, and entrepreneurial decisions. Washington has
historically attracted technology, aerospace, and other
innovation-driven firms and high-income individuals in part because
it lacked a personal income tax. Empirical studies of other states
that enacted or increased high-income taxes (or “millionaire
taxes”) often find measurable out-migration of high earners,
reduced in-state investment, and some dampening of capital
formation—effects that are larger when neighboring jurisdictions
remain lower-tax. Critics of the Washington measure argue that taxing
the portion of income above $1 million at nearly 10% (on top of
federal rates and the existing capital-gains excise tax) reduces the
after-tax return on successful innovation and high-growth ventures,
potentially discouraging the very activities that have driven much of
the state’s recent economic expansion. Supporters respond that the
tax affects only a tiny fraction of residents, that revenue will fund
public goods that support growth (education, infrastructure,
workforce), and that fairness considerations outweigh mobility risks.
The magnitude of any growth effects will depend on how the tax is
implemented, whether it survives legal and electoral challenges, and
how mobile the affected taxpayers prove to be in practice.
This tax represents a significant departure from Washington’s long-standing reliance on sales, property, and B&O taxes and continues the broader historical pattern of expanding the state’s fiscal capacity to support public services. Its ultimate durability will be determined by the November 2026 election results, subsequent court rulings, and future legislative choices.
Another Recent Tax Addition: Washington’s Capital Gains Tax
Washington enacted a tax on long-term capital gains in 2021 (ESSB 5096, codified in RCW 82.87). It took effect for sales or exchanges occurring on or after January 1, 2022. The tax is structured as an excise tax on the privilege of selling or exchanging certain capital assets, rather than a direct tax on income or property. This distinction was central to its legal survival.
Key features (as of 2026):
Applies only to individuals (including gains flowing through from pass-through entities in which the individual has an ownership interest).
Taxes long-term capital gains (assets held more than one year) that are allocated to Washington.
Standard deduction: originally $250,000; adjusted annually for inflation. For 2025 the deduction is $278,000 (the 2026 figure is published by the Department of Revenue each fall and cannot decrease).
Base rate: 7% on taxable gains above the standard deduction.
Higher tier (added by 2025 legislation): an additional 2.9% on the portion of taxable gains exceeding $1 million, producing a combined top rate of 9.9%.
Major exemptions: real estate (including primary residences and most other real property), certain retirement-account assets, and some other specified categories.
Credits are available for certain B&O taxes paid on the same transaction and for taxes paid to other jurisdictions on the same gains.
Legal history
Opponents challenged the tax as
an unconstitutional income tax under the 1933 Culliton v. Chase
precedent, which treated income as property subject to uniformity
requirements. In March 2023 the Washington Supreme Court upheld the
tax 7–2 in Quinn v. State, ruling that it is a valid
excise tax on the exercise of the right to sell or exchange capital
assets, not a tax on the property or the gain itself. The U.S.
Supreme Court declined review. Voters later rejected a 2024
initiative (I-2109) that would have repealed it.
Revenue and policy context
The tax was
originally projected to raise several hundred million dollars per
year, with proceeds largely directed to education-related accounts
(Education Legacy Trust Account and common-school construction).
Actual collections have varied with market conditions. It represented
the first major step by the Legislature toward taxing investment
returns after decades of reliance on sales, property, and B&O
taxes, and it paved the conceptual and political ground for the
broader 2026 Millionaires’ Tax (the 9.9% tax on income above $1
million scheduled to begin in 2028).
Interaction with the Millionaires’ Tax
Taxpayers
subject to both measures receive a credit on the income-tax return
for capital-gains tax already paid on the same gains. The
capital-gains tax continues to operate independently and applies at
lower thresholds than the Millionaires’ Tax.
Critics argue that layering a 7–9.9% state capital-gains tax on top of federal rates reduces after-tax returns on successful investments and can influence decisions about where high-growth entrepreneurs and investors locate or realize gains. Supporters contend it improves tax fairness by asking those who benefit from large investment profits to contribute more to public services, particularly education, without imposing a general wage tax.
The capital-gains tax remains in force as of October 2026 and forms an important recent chapter in the longer shift of Washington’s tax structure away from exclusive reliance on consumption (sales) and property taxes.
