Happy birthday Nhbenz!
Scouting for boys started in England around 1907 by a General Powell. He found out that boys were using his military scouting handbook on their outdoor adventures. It caught on and spread like wildfire. A man named William Boyce started BSA in America in 1910 I think. But he added a twist to what Powell had started by making BSA a business.
Long story short, yes Explorers are a part of the US BSA. I earned my District Award of Merit in BSA in 1994. I saw a group of boys through scouting from Tiger cubs up to Eagles. Its still neat how they still stop by now to tell me whats going on in their life.
Yeah, Yeah I know girls don't belong in BSA, but they were short on leaders since most gentleman have to earn a living and it takes alot of time and planning each week. I did the girlscout thing too dont worry lol.