The contras (some references use the capitalized form, "Contras") is a label given to the various U.S.-backed and funded rebel groups that were active from 1979 through to the early 1990s in opposition to the left-wing, socialist Sandinista Junta of National Reconstruction government in Nicaragua. Among the separate contra groups, the Nicaraguan Democratic Force (FDN) emerged as the largest by far. In 1987, virtually all contra organizations were united, at least nominally, into the Nicaraguan Resistance.