Alex, “what are ‘spelling and capitalizing Jeopardy! correctly while formulating my answer in the form of a question’?”
I do the same thing and have actually guessed the correct response before the Final Jeopardy reveal a few times. Last night was not one of those times–not even after the clue reveal–so the OP definitely beat me there.
The category was “The Commonwealth.”
I correctly predicted the question would be “What is Canada?”
I would immediately think of the folowing, but I don’t think a lot of people necessarily would, making them “not famous” like the ones I listed:
1927 – Lindbergh flies across the Atlantic solo.
1945 – End of WWII; first atomic bombs.
1969 – First Moon landing.
1976 – US Bicentennial.
2001 – First year of the new millennium; 9/11.
Right offhand, I can’t think of anything special about 1485 unless it has to do with daVinci or Michaelangelo. Or maybe Gutenberg? Martin Luther? The War of the Roses? 
1927 Lindbergh and Babe Ruth.
1485 I was thinking Bosworth Field. Those are just years that popped up in my head and I’m certainly not qualified to be a question writer for the show. And that is only using US/UK-centric references. You could go much deeper and worldwide and still remain true to the category.
How about 1453?
Fall of Constantinople?
I got Final Jeopardy once from the category “Alliterative Athletes”.
1620 as well, for a US audience.
Barry Bonds? (Mickey Mantle? Mark McGwire? Samma Sosa? Cassius Clay? My answer would depend on when this question was asked. ETA: Or rather, my question would depend on when this was answered.)
Somewhat of an aside, but I always thought Jeopardy! would be more interesting if they gave legitimate answers and wanted specific legitimate questions:
Host: The answer is … 21
Boop boop boop
Contestant: How much is 7 times 3?
BUZZ
Host: I’m sorry. The question we were looking for is “What was Jayne Mansfield’s waist size?”
Pilgrims arrive at Plymouth Rock; Mayflower Compact.
US goes to war against Great Britain; Napoleon invades Russia.
Battle of Borodino, burning of Moscow, Napoleon’s retreat from Russia (over the winter).
The way I play this is to guess what the CATEGORY will be before it is announced. One of these days it’s gonna be “FLAGS” and I’ll feel so smart!
I get a kick at the scene in She’s All That where Kevin Pollack shouts out totally reasonable but outrageously wrong responses to the questions. “Who’s on Mt Rushmore?” “Who is President Rushmore!”
“a copy of the Old Testament attributed to this printer sold for $ 5.3 million.”
“Who is Hewlett-Packard?”
I’ve only got FJ from the category alone once (“What is Charlotte’s Web?”).
But I did get a daily double before the answer was read. The category was something like “guitar gods” and the DD was the $1000 box. The other questions had all been revealed, and were something like “Who is Jimmy Page/Jimi Hendrix/etc” and the only one not mentioned at that point was Eric Clapton, who had to have been one of them. I wonder if, had I been on there, I would have had the guts to say in one breath “I’d like to make it a true daily double, and the question is ‘Who is Eric Clapton?’” Without even hearing the answer.
I wonder how many people realize that an answer will never be repeated during a show (at least I’ve never seen this happen), allowing you to use the process of elimination like this.