The United States will celebrate its Tricentennial in 2076, the next 100-year milestone after America250.
A tricentennial marks 300 years. Since the Declaration of Independence was adopted in 1776, adding three centuries places the next major anniversary in 2076. The 2026 semiquincentennial marks 250 years, so the tricentennial will arrive fifty years later.
The year 2076 also has a special connection to the earlier Bicentennial. In 1976, the country celebrated 200 years since the Declaration; in 2026, it celebrates 250 years; and in 2076, it will reach 300 years. These labels describe elapsed time from the 1776 declaration rather than the age of every institution now associated with the United States.
The future milestone is sometimes called the United States Tricentennial or the 300th anniversary of American independence. It should not be confused with the 300th anniversary of the Constitution, which would fall in 2087, because the Constitution was ratified in 1788.