Congress designated National Miners Day a national holiday "in appreciation, honor, and remembrance of the accomplishments and sacrifices of the miners of the nation."
An explosion in Monongah, West Virginia triggered the worst mining disaster in American history.
The demand for iron increased drastically. Knights needed it to create their armor, weapons, horseshoes and other gear.
Gold mining took off in the predynastic era. Egypt became a major gold producer in the region for the next 1,500 years.
