How the US acquired so much gold in the first place

Immediately following passage of the [Gold Reserve] Act [of January 30, 1934], the President Franklin D. Roosevelt changed the statutory price of gold from $20.67 per troy ounce to $35. This price change incentivized gold miners globally to expand production and foreigners to export their gold to the United States, while simultaneously by devaluing the U.S. dollar it reduced deflation. The increase in gold reserves due to the price change resulted in a large accumulation of gold in the Federal Reserve and U.S. Treasury, much of which was stored in the United States Bullion Depository at Fort Knox and other locations. The increase in gold reserves increased the money supply, lowering real interest rates which in turn increased investment in durable goods.