In 1970, a defining moment for black lesbian feminists occurred at the Black Panther's Revolutionary People's Constitutional Convention in Philadelphia, Pennsylvania. Several black lesbian feminists confronted a group of white lesbian feminists about what they saw as a racially divisive agenda. Following this event, several groups began to include and organize around Black lesbian politics. For example, in 1973, the National Black Feminist Organization was founded and included a lesbian agenda. In 1975, the Combahee River Collective was founded out of experiences and feelings of sexism in the Black Power movements and racism in the lesbian feminist movement. The primary focus of this collective was to fight what they saw as interlocking systems of oppression and raise awareness of these systems.