On 29 October 1969, at 10:30 p.m. (Pacific time), the first two letters were transmitted through him ARPANET. After the network fell. An hour later, after a few fixes, the first real remote connection between two computers was made.
It was the first network connection, something that later evolved into Internet that we all know.
But according to Charles Herzfeld, ARPA Director who oversaw most of its construction ARPANET:
The ARPANET was not made to be just a command and control system that can survive a nuclear attack, as many claim. The development of such a system was clearly a great military need, but it was not ARPA's mission. In fact, we would have been severely criticized if we had tried to do so. On the contrary, the ARPANET came out when we realized that there were very few large, powerful research computers in the country and that many researchers who needed to access them were geographically remote.
In his childhood, the ARPANET had only four "nodes":
at the University of California-Los Angeles Network Measurement Center with the SDS Sigma 7 computer.
at the Stanford Research Institute's Network Information Center, with the SDS 940 computer running the NLS (an early hypertext system and World Wide Web precursor).
At the University of California, Santa Barbara's Culler-Fried Interactive Mathematics Center with IBM 360 / 75. and
at the University of Utah School of Computer Science with PDP-10 of Digital Equipment Corp. operating on the TENEX operating system.
These computers, instead of being directly connected, were connected via Interface Message Processors (IMPs), which were the first network routers.
This would allow additional systems to be added as nodes in the network from each location with the weather. The idea was born by physicist Wesley Clark, who also designed the LINC, the world's first personal computer.
The first "letters" sent by UCLA to Stanford by UCLA student Charley Kline were actually two letters, "l" and "o".
In the second attempt, the full text of the message appeared, "login" passed through the UCLA Sigma 7 to the Stanford SDS 940 computer. Thus, the first two characters ever transferred from the precursor to the Internet were L, and O.
Until the moment when the ARPANET, had grown significantly, but was still used primarily by researchers and the military.
The ARPANET operated for the military until 1990 and until then the use of the network for anything other than government operations and research was illegal.
Then, the ARPANET has been largely replaced by the National Science Foundation Network (NSFnet). Although the Department of Defense has been using its own networks in MILNET since the mid-1980s, parts of the military have been using its networks. ARPANET in many internal documents in the early 1990s.
When the network shut down, Vinton Cerf, one of the fathers of the modern Internet, wrote a poem about ARPANET:
It was the first, and being the first, was the best,
but now we are laying it down to ever rest.
Now pause with me for a moment, shed some tears.
For auld lang syne, for love, for years and years
of faithful service, duty done, I weep.
Lay down thy packet, now, O friend, and sleep.