William Manson Seabron, 72, a retired Agriculture Department official who was active in church organizations, died of cardiac arrest Friday at George Washington University Hospital.

Mr. Seabron came to Washington in 1962 to become assistant to the director of personnel in the Agriculture Department. From 1964 to 1972, he was assistant to the secretary of Agriculture for civil rights. He then served as deputy director of the department's Office of Civil Rights until retiring in 1973.

He was given the Department of Agriculture's Certificate of Merit in 1972 and its Superior Service Award a year later.

Mr. Seabron was a resident of Washington, where he was a member of the Plymouth Congregational Church. He was a member of the church's board of deacons and vice president of its men's club.

A 32nd degree Mason and a Shriner, he was a member of the National Association of Intergroup Relations Officials and the Rock Creek Neighborhood Association.

Mr. Seabron was a native of Chicago and a graduate of the University of Iowa, where he earned a bachelor's degree in chemistry. He also had attended DePaul University in Chicago and the University of Michigan.

He was industrial secretary of the Urban League in Minneapolis from 1945 to 1950, then spent five years with the Urban League in Detroit. From 1955 until moving to Washington in 1962, he was deputy director of the Michigan Fair Employment Practices Commission in Detroit.

Survivors include his wife, the former Nevada Thornton of Washington; a son, Dr. Stephen M. of Takoma Park; two daughters, Deborah A. Seabron of Washington, and Carolyn S. Wilkins of Southfield, Mich. and four grandchildren.