When I graduated from high school in 1963...
The median income of all families in 1963 was about $6,200; but for families headed by college graduates, the median was $9,700.
But a high school graduate working under a strong labor union, for example General Electric or one of those major steel producing companies, could be hired at the lowest pay (clean floor & take out the garbage) and make more than a typical collage graduate working in a company without any labor union.
.