What you are saying is strictly, clearly incorrect.
In fact, not only has every person who has served as a SCOTUS justice been an attorney, but every person nominated has been an attorney. [0]
Stanley Forman Reed, to whom you are referring as the person who retired in 1957, attended but did not graduate from law school - perhaps that's the source of your confusion? In any case, Reed had a long, storied career as an attorney before being nominated to the Court.
Again: every person for whom a nomination has been submitted by a POTUS to the Senate has been an practicing attorney, barred in one or more US States. There has not been a single exception. And certainly no nomination even approaching "no legal background whatsoever."
0: https://en.wikipedia.org/wiki/List_of_law_schools_attended_b...