Seven
In 1837 there were 12 states that were slave.
Of the original 13 colonies, North Carolina and Rhode Island joined last, in November 1789 and May, 1790 respectively.
Massachusetts, and New York
United states and Britain
The members of the Constitutional Convention are responsible for creating the United States Census. In 1787, the US became the first nation to make a census mandatory. Article I, Section Two of the Constitution mandates that "Representatives and direct taxes shall be apportioned among the several states. . .according to their respective numbers. . ." In order to do that, a census would have to be taken to count the number of people. The first census took place in 1790. You can read more about the history of the census on Wiki or www.census.gov/history
Frederick Augustus Muhlenberg (born January 1, 1750 in Trappe, Pennsylvania; died June 4, 1801 in Lancaster, Pennsylvania), the first Speaker of the United States House of Representatives, served between April 1, 1789 and March 4, 1791, including the whole of 1790.
Virginia
1787-1790
In 1790, the United States of America consisted of the original 13 colonies, now designated as states, that had rebelled against Great Britain some 15 years previously. In the next year, the state of Vermont would also join the Union, with many more to follow over the years.
The exact number is unknown. However, civilian federal employees and their dependents living overseas were counted in the 1790 Census. This was crucial as private U.S. citizens who were not employed by the federal government were not counted. The U.S. Census is used for apportioning seats in the House of Representatives.
The representatives for New York grew in the 1792 elections due to the results of the 1790 census. In 1792 New York went from having six to ten representatives.
Rhode Island was the last of the thirteen original states to ratify the US Constitution on May 29, 1790.
1790
3,929,214.
All 13 of the original states ratified the Constitution. Delaware was the first on December 7, 1787 and Rhode Island was the last on May 29, 1790.
The state of Virginia had a population of 747,610 in 1790. This was the largest population of any of the 13 new states.
Two-thirds of the states needed to ratify the US Constitution for it to become law. This meant 9 states were needed. However, all 13 of the original states did ratify the Constitution with Rhode Island being the last one in 1790.