Pennsylvania, Rhode Island, South Carolina, Vermont, Virginia, West Virginia & Wisconsin remain in Civil War's United States.

In the thirty years leading up to the Civil War ... then sets fire to Pennsylvania Hall. 1845: Slaveholding Texas is annexed into the United States, sparking the Mexican War.

Hailed as a groundbreaking technical achievement, it came to symbolise the border between the Civil War North and South, separating free Pennsylvania ... project Outdated maps meant fresh ...