In early October 2018, several thousands of people fled gang violence from the Northern Triangle of Central America (NTCA) on an overland journey north in three separate groups colloquially referred to them as "caravans".

[2] In response to the northward migration, and according to Newsweek, U.S. President Donald Trump eventually made his decision to take a hard-line stance against illegal immigration on the Mexican border.

[3] In October 2018, what was then known as Operation Faithful Patriot was initiated to provide U.S. military assistance to U.S. Customs and Border Protection (CBP) in the southwest United States in confronting the approaching caravans.

[4][5] Trump ordered the operation on October 26, 2018, and United States Secretary of Defense Jim Mattis signed the deployment authorization later that day.

[8] Citing an unnamed source, KQED-FM reported the forces were being moved to marshaling areas in California, Texas, and Arizona and, from there, would respond to CBP positioning requests.

[12] By March, a plan was being prepared to ask the Defense Department for more federal troops to help with migrant processing, transportation and medical care in high-crossing areas.

[18] As of October 29, 2018, a full list of units participating in border support operations had not been released, but activated forces were said to include military police, in addition to combat aviation, combat engineer, medical, and civil affairs units totaling approximately 5,000 U.S. soldiers and 2,000 National Guard troops who are already deployed as part of the existing Operation Guardian Support.

The National Guards of Arizona, Texas, South Carolina, Oklahoma, Georgia, Missouri, Alabama, Florida, and Mississippi have contributed forces to the operation.