On October 29, 1969, at 10:30 p.m. Pacific Time, the first two letters were transmitted over the ARPANET. Then the network went down. An hour later, after some repairs, the first real remote connection between two computers was made.
It was the first network connection, which later evolved into the Internet we all know.
The ARPANET project was funded by the Advanced Research Projects Agency ( DARPA) and was created to explore technologies needed to develop a military network that could survive a nuclear attack.
But according to Charles Herzfeld, Director of ARPA who oversaw most of the construction of the ARPANET:
ARPANET was not built to be just a command and control system that could survive a nuclear attack, as many claim. Developing such a system was clearly a major military need, but that was not ARPA's mission. In fact, we would have been heavily criticized if we had tried to do that. Instead, ARPANET came about when we realized that there were very few large, powerful research computers in the country and that many researchers who needed access to them were geographically remote.
In its infancy, ARPANET had only four “nodes”:
at the Network Measurement Center at the University of California-Los Angeles, with the SDS Sigma 7 computer;
at the Network Information Center at the Stanford Research Institute, with the SDS 940 computer that used NLS (an early hypertext system and precursor to the World Wide Web).
At the University of California, Santa Barbara's Culler-Fried Interactive Mathematics Center, with the IBM 360/75. and
at the University of Utah's School of Computer Science, with the Digital Equipment Corp PDP-10 running the TENEX operating system.
These computers, instead of being directly connected, were connected through Interface Message Processors (IMPs), which were the first network routers.
This would allow additional systems to be added as nodes to the network from any location as needed. This idea was conceived by physicist Wesley Clark, who also designed LINC, the world's first personal computer.
The first “letters” transmitted from UCLA to Stanford by UCLA student Charley Kline were actually two letters: “l” and “o.”.
On the second attempt, the full text of the message, “login,” appeared, passed from UCLA’s Sigma 7 to the Stanford SDS 940 computer. Thus, the first two characters ever transmitted from the precursor to the Internet were L, and O.
By the time ARPANET was first exposed, it had grown significantly, but was still used primarily by researchers and the military.
ARPANET operated for the military until 1990, and until then, using the network for anything other than government operations and research was illegal.
ARPANET was then largely replaced by the National Science Foundation Network (NSFnet). Although the Department of Defense had been operating its own networks on MILNET since the mid-1980s, parts of the military were using ARPANET network connections in many internal documents in the early 1990s.
When the network was shut down, Vinton Cerf, one of the fathers of the modern Internet, wrote a poem about ARPANET:
It was the first, and being first, was best,
but now we lay it down to forever rest.
Now pause with me 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.
Without ARPANET, however, today's Internet would not exist.
