The contiguous United States
In 1878 the US was called the United States of America.
Because the US stands for the United States, short for the United States of America.
States
The Union States.
it called regional migratinon
It's the abbreviation of The United States of America.
Illinois i live there and its called the prairie state.
Pennsylvania
Creoles.
It was called the Confederacy or the Confederate States of America.
The 1920s were called the "roaring 20s" in the United States.
Those were the states that voted on the first approved US Constitution.