1834 was the "change over year" when the politicians in Washington got smart and reduced the gold content of the $2.50 and $5.00 gold coins. Prior to that the ratio between silver and gold was 15 to 1. Vast numbers of U.S. gold coins were exported and melted making them very scarce to rare collectors' items today. The Coinage Act of 1834 increased it to 16 to 1. Here is an "old tenor gold" piece that was made under the 15 to 1 ratio. There are less than 100 of these coins left. And here is an 1834 dated Classic Head $5 gold which was made to the 16 to 1 standard. This piece has "the plain 4" with the crosslet on the four. Here is an example of the 1834 "crosslet 4" variety. This coin is very scrace. This close-up photo shows the difference between the two.