When speaking of mint state coins minted prior to 1933, these coins were produced for the sole purpose of monetary transactions. The number of the coins that were produced each year was directly tied to the need for more currency and the availability of gold and silver. Through the years as the population grew, mintage figures increased as the demand for circulating currency grew.
For example, let’s look at the $2.50 Quarter Eagle. The first Quarter Eagle was produced in 1796 and had a mintage figure of just 963 coins. In 1821, 6,448 of the coins were produced and by 1836, the mintage was 547,986 coins. As these coins circulated through the populace as currency, the condition of them deteriorated, making examples in high grades very hard to acquire.