Alexander von Humboldt, a man with a pretty darn good moral compass for that time, thought it was the best thing ever—if it got rid of slavery. He visited with a handful of the U.S.’s first few presidents after his journey across Central America and had a great relationship with Jefferson in particular.

For context, Humboldt was a Prussian aristocrat and polymath. While he did advise the royal family he was generally disliked by the aristocratic class for being super progressive and undermining existing power structures. He hated Prussia so much he tried to live in Paris whenever he was in Europe.

Needless to say, others thought much less of the new state. All I know’s what Humboldt thought.

So to answer your question more broadly, it depends on who you asked.