A Bullionist is a person who believes in a precious metals backed monetary system. Up through 1964, the United States produced coinage made out of silver, and many other countries had also used silver (and gold) in their coinage through the same time period.
United States Congress passed the Mint and Coinage Act in 1792. It authorized the Federal Government's use of the Bank of the United States to hold its reserves, as well as establish a fixed ratio of gold to the U.S. dollar. Gold and silver coins were legal tender along with the Spanish Colonial coins that were popularly used during that era. In 1792 the market price of gold was about 15 times that of silver. Silver coins left circulation, exported to pay for the debts taken on to finance the Revolutionary War. In 1806 President Jefferson suspended the minting of silver coins. This resulted in a derivative silver standard, since the Bank of the United States was not required to fully back its currency with reserves. This began a long series of attempts by the United States to create a bi-metallic standard.
The Bretton Woods system, which marked the end of the use of bullion in monetary policy, established the rules for commercial and financial relations among the world's major industrial states in the mid-20th century. The Bretton Woods system was the first example of a fully negotiated monetary order intended to govern monetary relations among independent nation-states.
To learn more about bullionism, bullion investing, the bullion investing forum on CoinTalk.com is a good place to start. It's an active community of like-minded people who invest in gold and silver as well as collecting coins and the study of numismatics.