Congratulations! What a beautiful growing city.
In my game, after many attempts, i finally managed to reach 1500 population in hard mode, in 1930 or so (starting in 1850).
My method was to build a lot of tram lines (and at least a line trasporting the needed goods).
In that city I had only two train lines (one for passengers and one for cargo), but at least five tram lines and two bus lines.
Sadly, in that game, I was bankrupt in 1950, before reaching 2000 pops (I was near), because I built another two railway lines and went in deep red (while my tram lines where struggling with heavy traffic). The railways in hard mode are hardly profitable…