U.S. gold coins were originally meant for circulation. They were used to make as an easier way to carry more money. As the value of gold increased, so did the value of the gold coins. Eventually the value of gold increased too much to use them for circulation purposes. Shortly after they became used for collection purposes. There were many different types of U.S. gold coinage.
There are multiple types of U.S. gold coinage. Liberty Head Coinage was a major part of that, which included a $2.5, $5, $10, and $20 piece. They all shared a similar obverse with a left-facing Liberty head. The only major differences between these coins were their face value, size, and gold content. Another popular type of U.S. gold coinage are the Indian Heads. These coins include the $2.5, $5, and $10. Their designs differed more than their predecessors. Perhaps the most popular gold coin is the the Saint Gaudens Double Eagle. The design of this was reused for the 2009 Ultra High Relief Double Eagle. Some odd ball denominations also existed like the $3 Gold Coin and the $1 Gold Coin.
Much later on came what are known as "Modern Gold Coins." One major type of modern gold coins are the the First Spouse Gold Coins. These began the same time as the presidential coins. The 2009 Ultra High Relief Double Eagle was one of the only gold coins to have words engraved on the side of the coin.
Many U.S. gold coins are much more valuable today then they were so many years ago. This is because of the increasing price of gold. The amount of gold a particular coin has, mintage, mintmark and condition are factors that determine the rarity of these coins.
U.S. Gold Coins and their mintage years:
$1 Gold Coin: 1849- 1889
$2.5 Liberty Gold Coin: 1840- 1907
$2.5 Gold Indian: 1908-1929
$5 Liberty Gold Coin: 1839- 1908
$5 Indian Head Gold Coin: 1908-1929
$10 Liberty Gold Coin : 1838- 1907
$10 Indian Head Gold coin: 1907-1933
$20 Liberty Gold coin: 1850- 1907
Saint Gaudens Double Eagle: 1907-1933
First Spouse Gold Coins: 2007-2020
2009 Ultra High Relief Double Eagle