What is the formal anniversary term used for America250?

The formal anniversary term used for America250 is the United States Semiquincentennial.

“Semiquincentennial” combines Latin-derived elements meaning half of 500, or 250. It is the standard name for the 250th anniversary of the United States Declaration of Independence. The event is also sometimes called a sestercentennial, bisesquicentennial, or quarter millennium, but semiquincentennial is the principal official term.

The word follows the familiar pattern of centennial for 100 years and bicentennial for 200 years. It is less commonly encountered in everyday speech, which is why America250 is a much simpler public-facing name for the commemoration.

The United States Semiquincentennial is scheduled for July 4, 2026. Its predecessor was the United States Bicentennial in 1976, while the succeeding 300th-anniversary milestone is expected in 2076. The celebration is organized in part by the United States Semiquincentennial Commission, created by Congress in 2016.