Which chess players from 19th Century are best to study for an amateur?

For opening with 1.e4 or responding to e4 with ...e5; Wilhelm Steinitz.

The games of Morphy are great for tactics, but first I would study and memorize the tactics that the great players of the past, including the 19th Century, made famous which are included in these two interactive pages:

https://www.chess.com/article/view/chess-tactics--definitions-and-examples

https://chesstempo.com/tactical-motifs.html

After you know the tactics, you'll learn more studying games because you'll see how the players maneuver to get in position to use the tactics.

Additionally there are great books from the early 1900's that are legally-free and in e-book form. Here are some by Capablanca and Lasker I posted recently here. If the links aren't current, you should be able to find them with a google search:

Capablanca and Lasker books

This a comment I made on chess.com:

https://www.chess.com/forum/view/chess-mentor/im-new-to-chess-can-someone-help-me

There are some free books that are old but excellent for giving you a good basic understanding of all aspects of the game at the introductory tournament level.

One is Chess Fundamentals by 1920's World Champion Jose Capablanca.  It's here in English. This link is the legally free ("public domain") 1934 edition, to which a group named "Caissa Lovers" changed the old descriptive notation to modern algebraic notation and is relatively short - about 121 pages.

http://www.sources.com/SSR/Docs/Capablanca-ChessFundamentals.pdf

Also, there are public domain books by the 1894-1921 World Champion Emanuel Lasker. His Common Sense in Chess and his Manual of Chess are worth doing a google search to find.  They may be only available in descriptive notation, but it is not hard to learn.  Here are those two in descriptive notation:

http://www.simardartizanfarm.ca/pdf/-_Lasker_s_Manual_of_Chess.pdf

https://ia801408.us.archive.org/14/items/commonsenseinche00laskrich/commonsenseinche00laskrich.pdf

I found the following account of a 2013 comment explaining which old but-excellent chess books are now in the public domain (http://www.chesspub.com/cgi-bin/chess/YaBB.pl?num=1365847618):

thank you very much

"Which chess players from 19th Century..."