Congressman. Rainey was born a slave in Georgetown to Edward L. Rainey and his wife Gracia on June 21, 1832. His father, a barber, purchased the family’s freedom, and they moved to Charleston in about 1846. The elder Rainey also purchased two slaves. By 1860 Joseph Rainey had become a barber at Charleston’s fashionable Mills House hotel.
In 1859 Rainey traveled to Philadelphia where he married Susan (maiden name unknown). During the Civil War, Rainey was compelled to serve as a steward on a blockade runner, and then to work on Confederate fortifications. He fled with his wife to Bermuda in 1862 on a blockade runner and resumed barbering, first in St. George and then in Hamilton. In 1865 he returned to Charleston and-accompanied by his elder brother Edward-participated in the Colored People’s Convention at Zion Presbyterian Church. Attendees sought ways in which to advance “the interests of our people.” Rainey was also elected to represent Georgetown in the 1868 constitutional convention.
Rainey was one of the more conservative black leaders during Reconstruction. He favored implementing a poll tax as a requirement for voting if the revenues were devoted to public education. He also supported an effort to legalize the collection of debts contracted before the Civil War including debts incurred in the purchase of slaves. Neither measure passed in the 1868 state constitution. In 1870 Georgetown voters elected Rainey to the state senate, where he became chair of the Finance Committee. He was also a brigadier general in the state militia, and he served as an agent with the ill-fated State Land Commission. He attended the 1869 State Labor Convention, which lobbied the General Assembly for pro-labor legislation to protect black workers.
Rainey was the first black man to serve in the U.S. House of Representatives. He took his seat in December 1870, filling the unexpired term of Benjamin F. Whittemore. He was reelected four times to the first district seat, serving from 1870 to 1879. In Congress Rainey advocated passage of the 1872 Ku Klux Klan Act as a means to rid the state of that terrorist organization. He supported an amnesty bill to remove remaining liabilities on former Confederates while simultaneously promoting a civil rights bill sponsored by Massachusetts Senator Charles Sumner. The amnesty bill passed in 1874 and the civil rights bill was enacted in 1875.
From 1879 to 1881, Rainey was an agent with the Internal Revenue Service in South Carolina. An active entrepreneur, he invested in the Columbia and Greenville Railroad and was a director of the Enterprise Railroad, a black-owned corporation organized in 1870 to transport freight by horse-drawn street railway between the Charleston wharves and the railroad depot. In the early 1880s Rainey attempted unsuccessfully to manage a brokerage and banking business in Washington, D.C. He died in Georgetown on August 2, 1887 and was buried in the Baptist Cemetery.