America250 occurs 250 years after the Declaration of Independence.
The Declaration was adopted in 1776, and adding 250 years brings the anniversary to 2026. The commemoration therefore marks a quarter of a millennium since the Second Continental Congress announced that the Thirteen Colonies were independent states.
This anniversary follows the United States Bicentennial of 1976, which marked 200 years, and precedes the Tricentennial in 2076, which will mark 300 years. The arithmetic is simple, but the wording can cause mix-ups because the Declaration was adopted in 1776 while the formal signing ceremony continued into August.