In 1963 Congress passed the Equal Pay Act of 1963, which prohibited wage differentials based on sex.

The prohibition on sex discrimination was added by Howard W. Smith, a powerful Virginian Democrat who chaired the House Rules Committee.
He was a conservative who strongly opposed civil rights laws for blacks, but he supported such laws for white women.
   
Smith's amendment was passed by a teller vote of 168 to 133.

 
Historians debate Smith's motivation—was it a cynical attempt to defeat the bill by someone opposed to both civil rights for blacks and women, or did he support women's rights and was attempting to improve the bill by broadening it to include women?
Smith expected that Republicans, who had included equal rights for women in their party's platform since 1944, would probably vote for the amendment.
Historians speculate that Smith was trying to embarrass northern Democrats who opposed civil rights for women because the clause was opposed by labor unions.

Smith asserted that he sincerely supported the amendment and, indeed, along with Rep. Martha Griffiths, he was the chief spokesperson for the amendment.
For twenty years Smith had sponsored the Equal Rights Amendment—with no linkage to racial issues—in the House because he believed in it.
For decades he had been close to the National Woman's Party and especially Paul.
She and other activists had worked with Smith since 1945 trying to find a way to include sex as a protected civil rights category.
Now was the moment.
Griffiths argued that the new law would protect black women but not white women, and that was unfair to white women.
Furthermore, she argued that the laws "protecting" women from unpleasant jobs were actually designed to enable men to monopolize those jobs, and that was unfair to women who were not allowed to try out for those jobs.
The amendment passed with the votes of Republicans and Southern Democrats.
The final law passed with the votes of Republicans and Northern Democrats.
 However, in 1964 the NWP and Pauli Murray did succeed, with the support of conservatives and over the opposition of liberals, blacks and labor unions, to have "sex" added to the Civil Rights Act of 1964, thus achieving some of the goals sought by the NWP.
Pauli Murray was also instrumental in the inclusion of sex in Title VII of the Civil Rights Act.
Title VII of the Civil Rights Act prohibits the discrimination based on sex, which has been attributed to the betterment of women as a group.
In 1963 Congress passed the Equal Pay Act of 1963, which prohibited wage differentials based on sex.
The prohibition on sex discrimination was added by Howard W. Smith, a powerful Virginian Democrat who chaired the House Rules Committee. He was a conservative who strongly opposed civil rights laws for blacks, but he supported such laws for white women.    
Smith's amendment was passed by a teller vote of 168 to 133. 
 
Historians debate Smith's motivation—was it a cynical attempt to defeat the bill by someone opposed to both civil rights for blacks and women, or did he support women's rights and was attempting to improve the bill by broadening it to include women? Smith expected that Republicans, who had included equal rights for women in their party's platform since 1944, would probably vote for the amendment. Historians speculate that Smith was trying to embarrass northern Democrats who opposed civil rights for women because the clause was opposed by labor unions.
Smith asserted that he sincerely supported the amendment and, indeed, along with Rep. Martha Griffiths, he was the chief spokesperson for the amendment. For twenty years Smith had sponsored the Equal Rights Amendment—with no linkage to racial issues—in the House because he believed in it. For decades he had been close to the National Woman's Party and especially Paul. She and other activists had worked with Smith since 1945 trying to find a way to include sex as a protected civil rights category. Now was the moment. Griffiths argued that the new law would protect black women but not white women, and that was unfair to white women. Furthermore, she argued that the laws "protecting" women from unpleasant jobs were actually designed to enable men to monopolize those jobs, and that was unfair to women who were not allowed to try out for those jobs. The amendment passed with the votes of Republicans and Southern Democrats. The final law passed with the votes of Republicans and Northern Democrats.  However, in 1964 the NWP and Pauli Murray did succeed, with the support of conservatives and over the opposition of liberals, blacks and labor unions, to have "sex" added to the Civil Rights Act of 1964, thus achieving some of the goals sought by the NWP. Pauli Murray was also instrumental in the inclusion of sex in Title VII of the Civil Rights Act. Title VII of the Civil Rights Act prohibits the discrimination based on sex, which has been attributed to the betterment of women as a group.
National Woman's Party