The U.S. federal census was taken at the beginning of every decade to apportion the number of representatives that a state could send to the House of Representatives in Congress. In the absence of a national system of vital registration, many vital statistics and personal questions were asked to provide a statistical profile of the nation and its states. | The U.S. federal census was taken at the beginning of every decade to apportion the number of representatives that a state could send to the House of Representatives in Congress. In the absence of a national system of vital registration, many vital statistics and personal questions were asked to provide a statistical profile of the nation and its states. |