Thomas Kearns was born in 1862 in Oxford County, Ontario, Canada, to MargaretMaher and Thomas Kearns. He moved with his Irish immigrant parents to a farm inNebraska and there obtained a grammar-school education. The development ofmining in the West drew him in 1883 to Park City, Utah, where he worked,prospected, and developed with others the Silver King mine that made him amillionaire. He married Jennie Judge, with whom he had three children. Electedalderman in Park City, he was also a delegate to the 1895 state constitutionalconvention where he advocated an eight-hour work day.

The Democratic majority in the 1899 legislature had failed to elect a U.S.senator, leaving the seat vacant for two years. In late 1900 Kearns announcedhis candidacy and was elected the following year by a Republican-controlledlegislature. Some accused LDS Church President Lorenzo Snow of engineering theelection of Kearns, a Catholic. Well-informed on mining law, Kearns also wonrecognition in the Senate for his support of Theodore Roosevelt'sconservation/irrigation programs. He worked to secure regimental post statusfor Fort Douglas and for opening the Uintah Indian Reservation to settlement.When he failed to receive support for reelection, he bitterly denounced thepower of the Mormon Church in a Senate farewell speech in 1905.

Kearns and his partner David Keith had purchased theSalt Lake Tribunein 1901 and also launched the eveningSalt Lake Telegram. Kearns and theTribune supported the national Republican ticket in 1904 but backed thenewly organized American party in Utah. With continuedTribune supportthe American party won the Salt Lake City municipal election in 1905 and twosubsequent city elections. The editorial and news columns of theTribunepersistently attacked LDS Church leaders and their influence on politics; butby 1911 the tone had mellowed.

Kearns died of a stroke in 1918, eight days after being struck by a car atSouth Temple and Main streets. Under the direction of Mrs. Kearns, the Kearnsfortune built St. Ann's Orphanage (now a school), and the Kearns home, whichwas donated by her to the state in 1937 and is now the governor's officialresidence.