Here's what happened in about 150 years under "conservative" US government policies:
Grew from small, isolated, breakaway country to the richest, most powerful country on the planet, with the highest standard of living.
Here's what happened under "liberal" government policies:
- Declared our independence from Great Britain in the first place.
You have the right to be on Slashdot and argue about which ideology is better because of liberal policies.
Along the way, freed slaves and saw life expectancy become the highest in the world.
Lincoln was most assuredly not conservative. Republican, yes. Conservative, no. His policies resembled those of modern progressives more than modern conservatives, though even that is something of a stretch, because unlike 99% of modern politicians, Lincoln was actually a respectable statesman.
Contrast to what happened in "progressive"/socialist/liberal nations such as Venezuela, Greece, and the Soviet Union.
Progressive != socialist != liberal.
Additionally, Greece's problems stemmed from government overspending without enough taxation to cover the expenses. That's more similar to what Republicans do today than Democrats. And both Venezuela and Russia had problems where a few people at the top of the party essentially lived in luxury while the poor starved, which makes it more like a caste system than true socialism.
Besides, essentially zero modern progressives view socialism as the be-all and end-all of public policy, but rather as a useful tool to use in limited ways for the public good. That's radically different from a country that attempts to use pure socialism as its sole policy (which is exactly as foolish as using pure capitalism as the sole public policy).