This is a map of ARPANET circa May 1973 via David Newbury, who found it among his father’s papers. The first part of ARPANET was built nearly 50 years ago and became the basis of the modern internet. The network was so small in the early days that those circles and squares on the 1973 map represent individual computers and routers, not universities or cities.
See also An Atlas of Cyberspaces.