Where did the B52 originate from?

Assuming you are refering to the 1952 Bomber produced by Boeing and how it received that name. The US Defence Dept. gave out contracts for its planes to whoever came up with the best tender for the aircraft it required. The bombers it required had the prefix "B" not for Boeing but for bomber, as its fighter planes the prefix "P" [pursuit] . The prefix had no bearing as to who built them. As time and development wore on so did the numbers succeeding the prefixes.