Pennsylvania is the state that's abbreviated with PA. Pennsylvania was the second state admitted to the union, gaining statehood on December 12, 1787. The state capital of Pennsylvania is Harrisburg.
In terms of size, Pennsylvania is the 33rd largest state, but it has the sixth highest population. Pennsylvania shares a border with Delaware, New Jersey, Maryland, West Virginia, Ohio, and New York, as well as Lake Erie. Since 1802, Pennsylvania has had the nickname of the "Keystone State" because of its importance among the original 13 colonies and because of all the important documents that have been signed there including the Declaration of Independence.