U.S. Constitution turns 225 years old, governs 314 million citizens

Happy Constitution Day, our 314,395,013 fellow Americans.

That's the estimated population of the United States of Americas as of noon Monday, according to the U.S. Census Bureau.

The Census issued the estimate in commemoration of Constitution Day, the 225th anniversary of the signing of the Constitution on Sept. 17, 1787.

The United States operated under the Articles of Confederation after independence and before adopting the Constitution.

Also observed as Citizenship Day, all schools that get federal funds are required to hold educational programs on the Constitution and citizenship on Sept. 17.

The day traces its origin to 1940, when Congress passed a joint resolution requesting "I Am An American Day."

In 1952, Congress repealed this joint resolution and passed a new law moving the date to September 17 to commemorate "the formation and signing, on September 17, 1787, of the Constitution of the United States."

The day was still designated as "Citizenship Day" and retained its original purpose of recognizing all those who had attained American citizenship.

In 2004, Congress changed the designation of this day to "Constitution Day and Citizenship Day."

There are more citizens now than ever, whether they were born here or immigrated: On Sept. 17, 1987, the Census Bureau estimated the U.S. population was 243,636,172 on the 200th anniversary of the signing of the Constitution.

The first U.S. census in 1790 counted 3,929,214 residents.