The first U.S. Census was conducted in 1790 by Thomas Jefferson. It had 6 questions. As required by the U.S. Constitution, a decennial census has been conducted every ten years since then.
why have a Census?
In addition to obtaining an accurate population count, the information from the Census helps to determine how more than $400 billion of federal funding is spent on programs, services, and infrastructure improvements. The U.S. Census Bureau relies on assistance from all levels to ensure an accurate and complete count.