When the US government decided that the Internet backbone should be controlled by commercial companies - rather than government funded agencies - Network Access Points were created to transition and decentralise the Internet in the early 1990s. From 1986-1990 the backbone of the Internet was NSFNET; funded by the National Science Foundation.
Commercial use of the NSFNET backbone was prohibited. By the early 1990's congressional hearings led to laws (in the US) that allowed commercial use of NSFNET. NSFNET was decommissioned in 1995 - along with US government funding of the Internet backbone - and from 1991-1995 four Network Access Points contracts were given (by the NSF) to commercial companies. The Network Access Points replaced the NSFNET backbone. The four NAPs were:
Network Access Points were replaced by Internet Exchange Points (IXPs) after 1995, and no longer exist.