President Donald Trump's promise to use the National Guard to secure the U.S.-Mexico border isn't a new concept and is something the U.S. has done in the past for varying reasons.
After the U.S. seized Texas and American Southwest following the U.S-Mexico War, armed militias patrolled the border looking for runaway black slaves. The traditional Underground Railroad to the north was too far for slaves to travel so thousands attempted the journey south to freedom. Soon, a guerra sorda, or cold war, developed between the nations.
Tensions remained high between white settlers, Mexican-Americans and Native Americans in the newly acquired territory following the U.S-Mexico War.
Congress created the U.S. Border Patrol in 1924 and the agency slowly grew in size as its mission changed. At first, the agents sought to keep out Asian immigrants and later worked to stall alcohol trafficking in the Prohibition era. Slowly, it evolved into stalling unwanted migration from Mexico.
By: Swati Kaushal