Historically, the constitutions of most national organizations limited membership based on race or religion. However, these restrictions were eliminated in the 1960s and 1970s. [[Title IX]] explicitly allows single-sex organizations such as fraternities. | Historically, the constitutions of most national organizations limited membership based on race or religion. However, these restrictions were eliminated in the 1960s and 1970s. [[Title IX]] explicitly allows single-sex organizations such as fraternities. |