The America250 celebration was held 250 years after the Declaration of Independence.
The Declaration was adopted in 1776, and the semiquincentennial anniversary occurred in 2026. Subtracting 1776 from 2026 gives 250 years, which is why the event is described as America’s 250th anniversary.
This calculation concerns the Declaration’s adoption and the independence milestone it represents. It does not measure the age of every institution associated with the United States. The Articles of Confederation, Constitution, presidency, and federal government each have different origin dates.
The 250-year interval also explains the event’s formal name. A centennial is 100 years, a bicentennial is 200 years, and a semiquincentennial is 250 years. America250 is the shorter branding used for the nationwide commemoration.