Private pensions are a very recent phenomenon.
There were only about a dozen private pensions in 1900. The number grew to about 400 by 1930, mostly in education and in the banking, insurance and utility industries. Most older workers didn't have pension plans until the 1950s. Since 1996 the number of workers enrolled in employer sanctioned defined contribution accounts has exceeded those remaining in defined benefit programs. There is an entertaining short history of pension plans in the United States on Social Security's History web page by former SSA historian Abe Bortz., and a Detailed Chronology of the History of Pension Plans as well.