The liberals in the nineteenth century were pretty much in favor of anything that would give them instant advantages, even though this is not morally right nowadays, for example, slavery, and about women's rights, it wasn't good for the market too. The conservative were on the same way, but not looking too much to the market, thinking more about the moral side of the story, but even though they liked to think about moralism, they were all in favor of slavery and against women's rights too.
The purchase was negotiated by Livingston and others with France and added 530,000,000 acres to the United States. It was opposed by Federalists in the US.