What is the main idea of this map?
3 points
Min.
S. Dak
Wyo
wyc
low
Nebr
Co
Kans
M
Onda
N Mex
Republic of Texas, 1836-1845, annexed by U. S. 1845
Disputed Claimed by Texas 1836-1845, claimed by U. S. 1845-1846
Mexican Cession, 1848
Gadsden Purchase, 1853
Land acquired from Mexico
Land purchased from Spain
The territory explored by George Gadsden
The territory explored by Lewis and Clark

What is the main idea of map?