What term names the 250th anniversary of the United States Declaration of Independence in 2026?

The 250th anniversary of the United States Declaration of Independence in 2026 is called the semiquincentennial.

The word combines elements meaning “half” and “five hundred,” producing the sense of half of a 500-year period, or 250 years. It follows more familiar anniversary terms such as centennial for 100 years, sesquicentennial for 150 years, and bicentennial for 200 years.

The term is used for the national anniversary associated with July 4, 2026. America250 is the more accessible public name for the commemorative program, while United States Semiquincentennial is the formal historical label. Alternative terms, including sestercentennial and quarter millennium, have appeared, but semiquincentennial is the principal name used for the observance.

The anniversary commemorates the Declaration's adoption rather than the signing of the U.S. Constitution, the conclusion of the Revolutionary War, or the establishment of the federal government. Those milestones occurred in 1787, 1783, and 1789, respectively, and have different anniversaries.