Why did your parents not have social security cards in 1940?

My parents did not have social security cards in 1940 because the Social Security program was relatively new, having been established in 1935. Many individuals, particularly those in rural areas or from lower socioeconomic backgrounds, may not have applied for a card or been aware of the program's benefits. Additionally, the widespread issuance of social security cards became more common in the following decades as awareness and enrollment increased.