This article traces the changing sexual politics of the Southern Baptist Convention (SBC) from the 1950s through the 1980s. It argues that the moderates who led the denomination in the 1950s, 1960s, and early 1970s joined other supporters of “sexual containment” during the early Cold War to develop a theology about the salvific power of marital sex—and the personal, social, and national harm created by extramarital sex—which undergirded the sexual conservatism of the denomination's fundamentalist leadership who rose to power during the 1970s and 1980s. This analysis reframes our understanding of Southern Baptists within the broader religious right coalition as it reveals how the SBC's commitment to marital sexuality, which was forged during the early Cold War, informed its approach to later hot-button issues like abortion and homosexuality. Rather than simply reacting against the loosening sexual mores of the 1970s and 1980s or in favor of the rising visibility of other politically engaged Christians on issues of sexual morality, the SBC instead drew on longer traditions within the denomination to engage with a changing political and sexual landscape.