The gadsden purchase enabled the united states to do which of the following?

gain access to important natural resources in the southwest
increase crop production in the southwest
link to the southwest by railway system
provide better defenses against mexico

The Gadsden Purchase enabled the United States to link to the Southwest by railway system.

The Gadsden Purchase is a region of 76 845 km² of present-day southern Arizona and southwestern New Mexico that was purchased from Mexico by the United States in a treaty signed between US President Franklin Pierce who signed it on June 24, 1853 and the Mexican ruler Antonio Lopez de Santa Anna who signed it on December 30, 1853 and ratified by the United States Senate on April 25, 1854. The purchase included the lands south of the Gila River and west of the Rio Grande and it was made for the purpose of building a transcontinental railroad along the southern route of the United States. It also solved the pending border problems after the Treaty of Guadalupe-Hidalgo that ended the Mexican-American War.

in 1803 the louisiana purchase took place, doubling the size of the country. by 1840 almost 7 million americans had migrated westward in hopes of securing land and being prosperous. the belief that settlers were destined to expand to the west is often referred to as manifest destiny.

explanation:

b) race riots in several cities