Democrats were liberals going back to the 1830s, but the term had substantially different connotations and policy implications.
True but the Democratic party changed a lot from in the 40 years after that to where it no longer was a liberal party. The GOP wasnt liberal either but neither were the Dems, the only liberal party left in the late 1800 was the populist party and it stayed that way until the populists took over the Democratic party in 1896.
I would say the Democratic party has changed a lot more than the Republican party, as the GOP was always really the industrial party and from 1856-1876 that put them to the left of the Democratic party as the goals of industry at them time were to the left of Agrarians. That didnt make the GOP liberal though, just its interests temporarily put them to the left of the Democrats.
The William Jennings Bryan takeover of the Democratic Party was basically a US version of the Labour Party replacing the liberal party as the main left wing party in the UK and it happened ever earlier
