1. When were the first keys made?
The ancient Egyptians were the first to use a kind of key to open a door. They had a lock that was made up of a wooden bolt that fits into a slot. Movable wooden pins known as tumblers were fastened in the top of the slot. When the bolt slid into place, the wooden tumblers dropped into holes cut in the bolt. The bolt was held fast until the tumblers were lifted up with a key.