Racial categories, which have been on every U.S. census, have changed from decade to decade, reflecting the politics and science of the times.

How the U.S. government measures race has changed substantially since censuses began in 1790. Today, Americans differ on whether the government should ask about race.

There is a day for just about anything, including the world's population. Did you know that Every July 11th is World Population Day? This international day was established by the Governing Council of ...