This series of quizzes has really made me scratch my head at all the Englishmen who rag on America's imperialist tendencies. Because it seems the answer to "gained independence from in 19xx...." is always the UK.
I don't see many Brits talking about the USA's imperialistic tendencies. Maybe their obesity, ignorance of geography, silly sports, lateness to world wars, tolerance of school shootings, intolerance of universal healthcare... :p
I used the old trick of writing the name of the country in hope to get a freebie. Alas, I didn't think to add "city" to the answer. The only question I missed.
Although I did actually NOT eventually get it... :-(