I'm new to commemorative coins and I'm finding their history to be very fascinating. I was just curious as to which coins were dumped into circulation in bulk (or if all were at some point). I've read that the Columbian Exposition halves were dumped after the exposition committee gave them to bank as collateral. I've also read that the Stonewall Jackson halves were dumped by banks at face value when they couldn't sell them. Are there any other examples of this?