I always point out that slavery wasn't that long ago, but it's really hard to illustrate the point. Louis CK's joke that the period between now and slavery is two old ladies back to back helps. It also helps to know that John Tyler, born in 1790 and president in 1840, still has grandsons alive today.
Social Security is the most effective anti-poverty program in U.S. history. So why do some people hate it?