Company that gave us the Internet to be bought by company that gave us the Patriot missile

ARPAnet was a precursor, and did not use TCP or IP.

BBN's role was in two narrow fields: they built the simple hubs used at each end of ARPAnet, and one or two people wrote some of the first email programs.

Someone at BBN came up with the idea of a packet network, but so did about a zillion other people around the same time, and a group in the UK demonstrated the concept first. It was only after they demonstrated the concept that BBN dug out the memos written by a since-departed employee.

TCP/IP, the distinguishing feature of the internet, was written by a group completely outside of BBN.