The origins of the Pilgrim Holiness Church trace back to 1897, when Rev. Martin Wells Knapp and Rev. Seth C. Rees founded the International Holiness Union and Prayer League in Cincinnati, Ohio. Their goal was to promote holiness and revivalism through literature, associations, and missions. In 1900, the organization changed its name to the International Apostolic Holiness Union to emphasize a return to apostolic Christianity.
From 1900 to 1913, the movement experienced rapid expansion. Revival efforts led to the establishment of missions, churches, rescue homes, and schools, with missionaries being sent around the world, including to Africa, India, Japan, the West Indies, and South America. In 1905, the name was changed again to the International Apostolic Holiness Union and Churches, reflecting its development into a denominational structure. By 1913, it became known as the International Apostolic Holiness Church.
Between 1919 and 1925, a series of significant mergers contributed to its growth. In 1919, the Holiness Christian Church, which had begun in Pennsylvania in 1882, merged with the International Apostolic Holiness Church to form the International Holiness Church. In 1922, both the Pentecostal Rescue Mission (founded in New York in 1897) and the Pilgrim Church (established in Pasadena in 1917) joined, prompting a name change to the Pilgrim Holiness Church. Further mergers followed with the Pentecostal Brethren in Christ (Ohio, 1924) and the People's Mission Church (Colorado Springs, 1899) in 1925.
Leadership and governance evolved significantly between 1926 and 1958. In 1926, Rev. Winfred R. Cox and Rev. Seth C. Rees were elected as superintendents. A single general superintendent model was introduced in 1930, later transitioning to a broader leadership structure with a General Board and multiple superintendents by 1958. Notable leaders during this period included Rev. Rees, Rev. W. L. Surbrook, Rev. L. W. Sturk, and Rev. William H. Neff.
Organizational development during the 1930s through the 1950s saw the establishment of offices for missions, Sunday schools, education, and publishing. In 1942, organizational terminology was updated, with “assemblies” renamed “conferences.” The church also introduced the Pilgrim Pension Plan and supported the growth of educational institutions like Owosso College.
From 1958 to 1966, the Pilgrim Holiness Church expanded its international presence and updated department names, such as changing “Foreign Missions” to “World Missions.” This era culminated in 1968, when the Pilgrim Holiness Church and the Wesleyan Methodist Church agreed to merge, forming what would become The Wesleyan Church.