The majority of my collection is from the USA- they are very easily accessible, and in fact I've pulled the majority of them out of circulation, including every year of cent from 1933-2015.
But the majority of my collection is new. Post World War II new. I do have some older issues- and in fact my oldest issue since 2008 was an 1832 half dime that I purchased on my very first trip to a coin shop after I really, truly became a numismatist. (I had been collecting the State Quarters before that, but I don't truly consider myself a coin collector until April 2008. I didn't even know what mintmarks were for instance!) When I got that one, I had never heard of a half dime before. I just knew it was old and it only cost me $5. It's slightly bent but I don't care. It's not like I have not seen older US issues- I've seen, in person, as old as 1796, with the asterisk that I've also seen a 1652 Massachusetts shilling, technically a British colony issue.
For a time it almost seemed like I'd never get anything older than 1832. Until a few weekends ago, when I set my oldest US coin record by a wide margin- 1801! I have not yet scanned it and my pictures aren't great, but here they are-
I suspect this may be my oldest US for many years to come. The previous record stood for 8 years, and it would not surprise me at all if this one holds that record even longer- the 1700s in the US are just way too expensive for me. (another reason I love world coins- I can get back much farther in history, which is my main reason for collecting) and 1800 is right up there with them. But I love this one, and I am very glad I was able to add it to my collection.