The bygone times may send you gifts even when they get farther away. They shape the context and let them develop into something more sophisticated than just material objects with face value on them. The story of the silver dollar 1921 value is no exception.
The period of the early 1920s was transitional for countries all over the globe. Having been involved in World War I, each nation was to face consequences, i.e., exhaustion, but global relief. As for the US specifically, the postwar economy experienced inflation and a gradual yet dramatic shift from agrarian to industrial society. Even the least noticeable aspects were alternating.
Coinage was also subject to change. In 1918, Congress passed the notorious Pittman Act, which forced the US Mint to melt down 350 million silver dollars to support their allies and stabilize the silver markets after the war. Nevertheless, by 1921, it was needed to recoin the melted silver, as the government urgently wanted to replenish what had been destroyed. This is how the Morgan Dollar, which had been a representation of power and national pride, was revived for one final year.
However, there was something else happening in the numismatic world. The war had ended in 1918, and the nation was also calling for symbols commemorating peace rather than hardships and recovery in the first place. Numismatists from different associations proposed the idea of paying tribute through new coins, which were soon released by the US Mint. Thus, 1921 became the first year of the Peace dollars series, i.e., a new chapter in the American monetary system.