Leroy Theodore Matthiesen was born June 11, 1921, in Olfen, an unincorporated community, in Runnels County, Texas. He was ordained as a priest for the Diocese of Amarillo on March 10, 1946. After receiving a master's degree in journalism in 1948, he was appointed editor of the diocesan newspaper The West TexasCatholic, which featured his column “Wise and Otherwise” until 1998. In 1954 he became the founding pastor of St. Laurence Parish in Amarillo. In 1961 he received another master's degree, this time in secondary school administration, and in 1962 was appointed rector of St. Lucian's Preparatory Seminary in Amarillo. He was awarded a Doctorate of Letters in Journalism in 1961, and in 1968 he was named Principal of Alamo Catholic High School. In addition, for nine years he was pastor of St. Francis Parish near Amarillo. Consecrated Bishop of the Amarillo Diocese in 1980, he served until his retirement in 1997. As bishop, he took several controversial stands, most notably a call to conscience to the workers of Pantex—the final assembly plant for all nuclear weapons in the U.S., as well as a call for a stay of execution for a man convicted of killing a nun in an Amarillo convent. Matthiesen admitted eight priests into the Diocese of Amarillo after they had undergone treatment following accusations of sexual impropriety. When they were removed from the diocese by Matthiesen's successor, John Yanta, Matthiesen raised money to help three of the former priests. His most controversial priest assignment are John Salazar and Ed Graff. Both of these priest were known to be serious sexual abusers and Matthiesen was warned not to assign them to parishes by other Church officials.
In his retirement he published three books: Wise and Otherwise: The Life and Times of a Cottonpicking Texas Bishop ; The Golden Years: The History of St. Laurence Cathedral in Amarillo ; and Lieber Bernard und Elise: The Lives and Times of a German Texas Family. Bishop Matthiesen received the Isaac Hecker Award for Social Justice in 1984 and the Ketteler Award for Social Justice in 2002. In 2009, he was presented with the Teacher of Peace Award from Pax Christi USA, which promotes nonviolence, disarmament and human rights. Matthiesen worked with other denominations and religions, as well as secular organizations devoted to peace and social justice. He was a strong supporter of the Peace Farm, an organization formed in witness to nuclear bomb assembly at neighboring Pantex.
