When elder brothers Newton, James, and Virgil went off to the American Civil War, they left their young teenage brothers Wyatt and Morgan to tend the family farm. James and Morgan grew up close, with a shared wish for adventure and a dislike of farming. Before adulthood, teen-aged Morgan followed James Earp to Montana for a couple of years. Later he was with Wyatt on the Western frontier.
In spring 1868, his father Nicholas Porter Earp and his siblings Ginnie, Warren, and Adelia returned to the mid-west and Lamar, Missouri, where Nick became the local constable. By November 17, 1869, Nick resigned to become Justice of the Peace. Wyatt, who had followed them to Missouri, was appointed constable in place of his father.
In early 1870, Wyatt married Urilla Sutherland, but she died later that year shortly before she was due to have a baby. Shortly afterward, Wyatt, James, Virgil, and Morgan got into what witnesses described as a "20-minute street fight" with Urilla's brothers and other relatives over the alleged bootlegging activities of both families.
Sometime between 1871 and 1877, Morgan met Louisa Alice Houston, the daughter of H. Samuel Houston and Elizabeth Waughtal. Louisa (born January 24, 1855) was the second eldest of 12 children.
