Member SCF rogdcam's part of his posts on the subject.
Quote: On January 13, 1937, the first shipment of gold from the New York Assay Office and the Philadelphia Mint would be made to the Bullion Depository at Fort Knox. Ships arrived semi-weekly between its first shipment in mid-January through June 17 of the same year. The United States Post Office oversaw the shipments as the gold would be transported from postal trucks onto trains accompanied by municipal police escorts. The train cars were armored and all postal workers were chaperoned by soldiers, mint guards, and secret service agents. A number of decoy train cars were employed as the gold was transferred from trains to Army trucks protected by another wave of soldiers and combat vehicles before making its way to the depository.
In this wave of gold transfers to the new building at Fort Knox, over 157 million troy ounces of gold was moved. After almost six months of movement, the entire shipment itself ended up representing nearly 45 percent of the total amount of United States gold reserves at the time. Four years later in early March of 1941, another shipment of over 258 million troy ounces was moved from the New York Assay Office to the bullion depository. This shipment to the vaults at Fort Knox, added to what was already being stored, increased the total amount of United States gold reserves represented to over 65 percent This new wave required seven months' time and countless train cars, moving vehicles, workers, and security measures.