No, this is the first time liberalism exists in the historical record. It's possible that the Mohists had developed liberalism before the Burning of the Books and the Burying of the Scholars (thus removing it from the historical record, along with most of the rest of the history of China up to that point) and of course the books that survive from before Gutenberg are relatively few in number.

If the Vikings in Essex had a well-developed liberal theory, for example, we'd have no idea of it, because none of their writings survive. (There were lots of slave graves, though, so they probably didn't put it into practice any more than Jefferson did, if they did have it.) There are some less depressing archaeological finds like Çatal Höyük, whose setup suggests hunter-gatherer-like egalitarianism, but we really have no idea what their philosophy was or what kinds of freedoms they enjoyed or valued; by the time cuneiform was invented, Çatal Höyük had been abandoned for 2500 years, after 2200 years of prosperity.

But there's really nothing resembling liberalism in classical Rome or Greece or medieval Islam or ancient Egypt or the Vedas, and it's quite a stretch to read liberalism into the Mozi or the Laozi.

I don't think it's such a sudden collapse, though. Liberalism has always been just one ideological current among many in the US, and there has never been a time when the US fully lived up to its ideals. Indentured servitude, chattel slavery, the Trail of Tears, the Comstock Act, Prohibition, imprisoning people for pacifism, the Indian schools, J. Edgar Hoover's deep state, the draft, Jim Crow, the imperialist conquest of the Philippines, the Chinese Exclusion Act, mass imprisonment, the Sonny Bono copyright extension act, the plea-bargaining system, Obama's mass deportations, the Comics Code, civil forfeiture, the FCC granting local media oligopolies, and the MPAA ratings system are all incompatible with liberalism, as I see it.

But I do think the last 25 years have seen a decisive turn to the Right in this sense; the main political debate in the US is no longer between liberalism and conservatism, but between progressivism and conservatism, both of which are opposed to liberalism.