In today’s New York Times, it is noted that Social Security’s original architects did not anticipate a major advance in the 20th century: women’s progress in market work, and how that progress would fill Social Security’s coffers.
Once they turn 62 years old, married people, widows and widowers are eligible for Social Security, regardless of whether they ever worked for pay during their lifetimes. When Social Security was in the planning stages, it was expected that most working-age couples would have only one person working (and thereby paying the payroll tax) — typically the husband. Yet when these couples retired, Social Security would pay benefit checks to both of them as long as they lived. See full article with cite to book on this topic: