The American Civil War, 1840–1877 · THE MAP IN
Map of the United States in 1840
A continent of rival claims
The United States in 1840: A continent of rival claims. The map shows who held what: The Union, Mexico, 1840–54.
Open this map in the interactive atlas →
WW2 is free in full, and chapter 1 of every atlas is free. A free account opens 3 more chapters a day. Starter, at $9 a month, opens all 21 with no daily limit — see the plans.
Free printable American Civil War study guide, sent by email ↓
On the ground
- Mexico City claimed the far north, including Alta California and Nuevo México, beyond the Adams–Onís line established by the US–Spanish border treaty of 1819. In fact, Comanche, Apache, Navajo and Ute nations held the region as much as Mexican settlers did.
- The slaveholding Republic of Texas had been independent since 1836. The United States recognized it in 1837; Mexico never did.
- Texas claimed the Rio Grande as its boundary, while Mexico claimed the Nueces. Taylor’s army marched into the disputed strip in March 1846, and the war began there.
Related maps
THE FREE PRINTABLE STUDY GUIDE
Get the printable study guide for The American Civil War free. I’ll send you a few short letters, then one when a new atlas opens. That’s all. — Paul
NO TRACKING · YOUR ADDRESS IS USED FOR THE DISPATCH AND NOTHING ELSE · UNSUBSCRIBE ANYTIME