What were the border states in 1861?

Along the U.S.A.-C.S.A. border, the states clearly on the Union side were Maryland, Pennsylvania, Ohio, Indiana, Illinois, Iowa and Kansas, the states clearly on the Confederate side were Virginia, Tennessee and Arkansas, and "on the fence" were Kentucky and Missouri.

The states along the border between the U.S. and the U.K.'s North American territories were Maine, New Hampshire, Vermont, New York, Pennsylvania, Ohio, Michigan and Minnesota.

The only U.S. state bordering México was California, and the only C.S.A. state bordering México was Texas.