It's Wiki , I know, but for all you Wiki Nuts...
Quote from Wikipedia:
In 1958, President Dwight Eisenhower asked a joint session of Congress to pass the Equal Rights Amendment, the first President to show such a level of support for the amendment. However, whenever the ERA was proposed the Hayden Rider was added; this would make the amendment unacceptable to the National Woman's Party, who would then ask that the ERA be withdrawn.
The Republican Party included support of the ERA in its platform beginning in 1940, renewing the plank every four years until 1980.[8] The ERA was strongly opposed by the American Federation of Labor and other labor unions, who feared the amendment would invalidate protective labor legislation for women. ERA was also opposed by Eleanor Roosevelt and most New Dealers. They felt that ERA was designed for middle class women but that working class women needed government protection. They feared that ERA would undercut the male-dominated labor unions that were a core component of the New Deal coalition. The amendment was opposed by most northern Democrats, who aligned themselves with the anti-ERA labor unions but the ERA was supported by southern Democrats and almost all Republicans.[8] In 1944, the Democrats made the divisive step of including the ERA in their platform, but the Democratic Party did not become united in favor of the amendment until Congressional passage in 1972.[8] The main support base for the ERA until the late 1960s was among middle class Republican women. The League of Women Voters, formerly the National American Woman Suffrage Association, opposed the Equal Rights Amendment until 1972, fearing the loss of protective labor legislation. Despite this, the amendment kept in line with the views of women's rights advocated by early feminists like Lucretia Mott, Elizabeth Cady Stanton, and Susan B. Anthony.