According to The Red Book's Peace Dollar book, 47% of all silver dollars from 1878-1904 were melted down to help the British cover their paper during the end of WWI. Zee Germans were successful in their propaganda machine in scaring the Indian population into hoarding silver. So, we helped the British out and sold them a lot of silver for $1 per .77 oz of pure silver, plus 1.5 cents per coin for smelting and transport. This depleted the US Treas of silver dollars and voila, the 1921 Morgan was minted from fresh silver from domestic mines. Hope that helps some. It's all in the Official Red Book's Peace Dollar guide. Thank Zee Germans for all this melting and the 1921 Morgan. ;-P