So mothers who have stayed home to raise their children get nothing?
https://www.ssa.gov/history/genrev.html
The Design of the Original Social Security Act
The new social insurance program the Committee on Economic Security (CES) was designing in 1934 was different than welfare in that it was a contributory program in which workers and their employers paid for the cost of the benefits—with the government’s role being that of the fund’s administrator, rather than its payer. This was very important to President Roosevelt who signaled early on that he did not want the federal government to subsidize the program—that it was to be “self-supporting.” He would eventually observe: “If I have anything to say about it, it will always be contributed, both on the part of the employer and the employee, on a sound actuarial basis. It means no money out of the Treasury.”