After silver was discovered in Tombstone in 1877, Clum moved to Tombstone and began publication, on Saturday, May 1, 1880 of "The Tombstone Epitaph". He organized the "Anti-Chinese League", and a "Vigilance Committee" to end lawlessness in Tombstone, and his association with that group helped get him elected as Tombstone's first mayor under the new city charter of 1881. While mayor he became lifelong friends with Wyatt Earp and became one of his greatest supporters. In December 1880, his wife Mary had a daughter Elizabeth, called Bessie, but Mary died soon after on December 18, 1880. Elizabeth was sickly and died the following summer.