I used to collect coins, but I never really had the money to assemble "sets" of coins so I just bought coins I liked.
Nowadays, though, I collect "history". Sometimes that history is coins, sometimes it's currency. I don't know much about currency, I just know what I like.
It's been over a year since my first and only visit to Hawaii. While there I learned some amazing history, including much about the monarchy. Throughout most of the 1800s Hawaii was an independent kingdom, and 'Iolani Palace in Honolulu is, in fact, the only (formerly) royal palace anywhere in the United States. Today I bought an 1883 quarter dollar coin with the image of Kalakaua on it, my only coin from the Kingdom of Hawaii.
After the Pearl Harbor attack in 1941 there were reasonable fears of a Japanese invasion of Hawaii. To prevent the Japanese from capturing a large amount of American currency, the military governor ordered that US currency be recalled and in 1942 new currency was issued. In fact, it was old American currency but had the word "Hawaii" stamped on it on the front and back. If the Japanese invaded Hawaii, the "Hawaii" currency could then be demonetized. Today I bought a $20 Hawaii note.
Hawaii's history is as fascinating and rich as the islands are beautiful.