The answer is they didn't have ratings! Winning / placing in tournaments meant you were a good / better player.
As for calculations done today to give them a rating, yeah, at least one guy did that:
http://www.chessmetrics.com/cm/
Before ELO rating system...
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thx shell-knight. that's what I figured.
Arpad Elo released a book called "The Rating of Chess Players, Past and Present" in 1978, here's a link to a free pdf scan of the 2nd edition, released 1986:
https://gwern.net/doc/statistics/order/comparison/1978-elo-theratingofchessplayerspastandpresent.pdf
Two separate appendices in the back list ratings for both "modern" (as of '86) and historical players, on pages 184-217. They're alphabetized instead of ordered by rating, so you can't see at a glance who was the top rated of them all.
But I combed through both appendices and found it was Fischer at 2740, with Capablanca in 2nd at 2725(that would have been a match to see eh). Bottvinnik and Kasparov both in 3rd and trailing very closely at 2720. Hardly anyone else broke 2700 at all, including Karpov at 2700 and maybe two or three others.
I was wondering today before the ELO or Harkness rating systems were used by FIDE and USCF, how were players rated in the days of say Alekhine, Lasker, Capa or Steinitz? Have there been any calculations of these players that tell us what their strengths were in ELO, adjusted from their previous rating systems?