When I think Socialist/Communist, really all I can think of is Marx or Russian Socialists like Lenin or Stalin. If I was An American socialist in the 1890's, what would I be reading exactly? What would be the central books and works? Would I have preference toward American Socialists, or German?
Likely similer things to what european socialists would have read, Engels, Marx and Kautsky were all big influences on socialism at the time, in America Daniel De Leon began was a somewhat prominent American socialist, you also may have read anarchists like Bakunin and Proudhon. Marxist Internet Archive is fantastic for finding stuff like this. Specific things you might have read might be The Economic Doctrine of Karl Marx by Karl Kautsky, Das Kapital by karl Marx, What Is Property by Proudhon or God and the State by Bakunin. All of this is available at Marxist Internet Archive, as is stuff by Debs himself if you're interested in that.