Peter Ernest Dietz was born on July 10, 1878, in New York City. He was the second child in a family of ten. His parents, Frederick and Eva (Kern) Dietz, were German immigrants. Frederick Dietz, a varnisher by trade, was frequently unemployed, and his children grew up in considerable poverty.
At an early age, Peter determined to enter the priesthood. He attended a parish school conducted by the German-based Redemptorist Fathers, and in 1894 entered St. Mary's, a Redemptorist college in North East, Pennsylvania. Ill health forced his withdrawal two years later but, after an interim as a paperhanger and painter, he studied at St. Francis Xavier College in Manhattan (1897 - 1899) and St. Bonaventure College in Allegany, New York (1899 - 1900), in preparation for admission to a seminary. In 1900, having become acquainted with several priests of the Society of the Divine Word, Dietz went to study at the society's seminary in Moedling, Germany. He therefore returned to the United States in 1903 and continued his studies at Catholic University in Washington, D. C.
Dietz had decided to devote his priestly career to the cause of the workingman, responding to the call for such work by Pope Leo XIII in his 1891 encyclical Rerum novarum. In Washington, D. C. his interest in social problems was encouraged by his friendship with Walter H. R. Elliott, a liberal member of the Paulist Fathers, and William J. Kerby, a pioneer Catholic social scientist who in 1910 helped found the National Conference of Catholic Charities. he was ordained a priest in December 1904 and was assigned as assistant pastor to a church in Elyria, Ohio.
The Catholic church, Dietz felt, must join in the effort to eliminate social injustice if it wished to retain the loyalty of Catholic workers and stem the drift toward socialism. Among the chief elements of the program he evolved were the creation of a unified national Catholic reform movement, the organization within the trade union movement of Catholic workers to combat socialism, and the establishment of a Catholic school of social service. Dietz worked initially within the socially conscious Central Verein, a national federation of German Catholic beneficial societies. As English-language editor of the Verein's Central Blatt and Social Justice (1909 - 1910), he worked closely with the Ohio Federation of Labor on a legislative program and lobbied actively for its passage by the state legislature.
Dietz's national efforts began in 1909. Attending the convention of the American Federation of Labor that year, he was impressed by the success of the Presbyterian minister Charles Stelzle in establishing closer ties between the trade union movement and the Protestant churches.
Dietz thereupon organized the Catholic delegates into the Militia of Christ for Social Service, of which he became executive secretary. Intended to include all Catholic unionists and to provide programs of social education and social action, the militia was endorsed by most Catholic bishops and labor leaders, who saw it as a useful ally in the A. F. of L. 's internal struggle against socialism. Yet, though the militia maintained a presence at national conventions, it remained a small organization, never attracting more than 700 members, and exerted little influence. It ceased to exist in 1914. Meanwhile much of the militia's program had been adopted by the American Federation of Catholic Societies, which in 1911, at Dietz's urging, established a Social Service Commission with Dietz as executive secretary. Besides supporting the programs of organized labor, the commission concerned itself with the problems of immigration and scientific social work, and attempted to educate Catholics on the need for reform.
In 1915 Dietz organized the American Academy of Christian Democracy, a school to train young Catholic women to become professional social workers. Originally established at Hot Springs, North Carolina, in facilities provided by a wealthy Catholic laywoman, the school was moved in 1917 to Cincinnati to afford students better opportunities for urban field work.
Following World War I the American Catholic bishops consolidated the church's social service activities into the National Catholic Welfare Conference, a permanent organization of the type Dietz had long advocated. Dietz was consulted about the establishment of the body's Social Action Department but was offered no role. In the unfavorable atmosphere of the postwar period, his militancy and his partisanship toward labor gained him many enemies, as did his abrasive personality. Continuing in the leadership of his school, Dietz also became involved in Cincinnati trade union activities, acted as a mediator in several labor disputes, and helped set up an industrial council plan in the city's building trades. But opposition to his efforts by the Cincinnati Chamber of Commerce led in 1923 to his expulsion from the archdiocese by Archbishop Henry Moeller and the closing of the American Academy.
Dietz was never again active on the national scene. Appointed pastor in the rural community of Whitefish Bay, Wisconsin, in the diocese of Milwaukee, he spent the rest of his life there, building up his parish, St. Monica's. He stayed in close touch with the labor movement, however, and in his community helped organize cooperatives and credit unions. In later years Dietz suffered from hypertension and at the time of his death was nearly blind. He died in Milwaukee at the age of sixty-nine.
Peter Dietz was a seminal figure in the Roman Catholic reform movement. He jarred the church's social conscience, and made the church more responsive to the needs of workers in a modern, industrialized America. He was founder of the National Labor College - the first of its kind in America - where unionists attended lectures, conferences, and retreats.
Dietz was a nervous, restless man, subject to headaches and fits of melancholy. Plagued by neuralgia, he was often irritable, abrupt, and suspicious. He lacked the social graces, and though his underlying qualities of sympathy and honesty won him many close friends, he frequently alienated more casual acquaintances.
