Answer:
Before the secession of Texas, Mexico comprised almost 4,400,000 km2, but by 1849 it was just under 2,100,000 km2. Another 78,000 km2 were sold to the U.S. in the Gadsden Purchase of 1853, so the total reduction of Mexican territory was more than 55%, or 2,300,000 km2.
Explanation:
"Treaty of Guadalupe Hidalgo". www.ourdocuments.gov. Retrieved June 27, 2007.
