Born in New York City on July 10, 1824 into a poor Irish family, King was indentured as an apprentice to a jeweler in Manhattan at the age of 9.

[1] During the Mexican-American War, King's friend and subsequent ranching and steam boating partner, Mifflin Kenedy, enlisted as ship master.

After the Battle of Brownsville, King Ranch was attacked by Union troops Christmastime 1863 by 80 men led by Captain James Speed.

When troops fired on the house, Alvarado was killed attempting to warn the soldiers that there were women and children inside.

The troops searched the property for King, vandalized the house and took the ranch hands as prisoners.

King continued to work the cotton trade throughout the war, and stayed in Matamoros, Mexico waiting to see if his request for amnesty from the President was approved.