On this date in 1788 — 225 years ago — that the Constitution of the United States was formally established, transforming the loose organization of the states under the Articles of Confederation into a more perfect union. Besides securing the rights of citizens and establishing the limits of government authority, the Constitution calls for a census every 10 years, to ensure that seats in the House of Representatives reflect the distribution of the U.S. population. The 1790 Census found 3.9 million resident Americans, and when the first Congress convened, the House had 59 members. Today, California alone has 53 seats in the House, and the 2010 Census found the population of Los Angeles alone is around 3.8 million. Profile America is in its 17th year as a public service of the U.S. Census Bureau.