The ARPANET project began with its seed ideas, as early as 1962. From the page below, you can read:
"First ARPANET IMP log: the first message ever sent via the ARPANET, 10:30 pm, 29 October 1969."
The direct answer to your question, then, is sometime between 1962 and October 29, 1969, depending on your definition of 'constructed'.
Development of ARPANET was started in 7 April 1969 by BBN Technologies and was completed later the same year. The ARPANET is the progenitor of today's internet.
ARPANET was developed
In 1969, ARPA funded the creation of the ARPANET. The ARPANET was the precursor to today's internet and was initially connected Stanford, University of California's campuses, and the University of Utah.
ARPANet was the forerunner to the modern internet. After World War II the American Government set up the Defence Advanced Research Projects Agency (DARPA). One of their tasks was that they had to design a communications system that would not collapse if part of it was knocked out by a bomb. ARPANet was the result of this, in about 1969. In the following decades more networks were set up and linked together. Common standards between all these systems were agreed upon and in 1989, the internet came into being.
One of the first "networks" that lead to the internet was the ARPANET in august of 1962 it was created, and the first node (point) on it was University California Las Angeles (UCLA) on September 2nd, 1969. It then moved through Stanford Research institute, University of California Santa Barbara, and through the University of Utah's Graphics Department. This is the growth of ARPANET (as taken from http://en.wikipedia.org/wiki/ARPANET)"In March, 1970, the ARPANET reached the U.S. East Coast, when an IMP at BBN itself was joined up to the network. Thereafter, the network grew quickly: 9 IMPs by June of 1970, and 13 by December; 18 by September, 1971 (at which point twenty-three hosts, at universities and government research centers, were connected to the ARPANET); 29 by August, 1972, and 40 by September, 1973. At that point, two satellite links, across the Pacific and Atlantic Oceans to Hawaii and Norway (Norwegian Seismic Array) respectively, had been added to the network. From Norway, a terrestrial circuit added an IMP in London to the growing network. By June 1974, there were 46 IMPs, and the network reached 57 in July, 1975. By 1981, the number of hosts had grown to 213, with a new host being added approximately every twenty days. After the ARPANET had been up and running for several years, ARPA looked for another agency to hand off the network to; ARPA's primary business was funding cutting-edge research and development, not running a communications utility. Eventually, in July 1975, the network was turned over to the Defense Communications Agency, also part of the Department of Defense. In 1983, the U.S. military portion of the ARPANet was broken off as a separate network, the MILNET. Prior to this there were 113 nodes on the ARPANet. After the split, that number was 45 nodes with the remainder moving to MILNET."The idea of an internet came from Xerox Network Services (yes the Xerox we know of today!) when they worked toward making a standard we know of today called TCP/IP (Transmission Control Protocol/Internet Protocol)In 1973, Norway followed suit and made the NORSAR, and ARPANET made a connection. Later on that year, these we transformed to the TCP/IP and this protocol became standard to the internet we know of today.Since the commerical use of ARPANET was forbidden, the exact definition of commerical use was so unclear, UUCPNET became formed and connect to ARPANET, due to administrators "casting a blind eye" onto their connections. Larger companies began using UUCPNET and in the 1980s, dialup on the west coast was formed by companies like UUNET, PSINET, NETCOM, and Portal Software. In 1986 a company on the east coast began providing dial up access to UUCPNET and this company was called world.std.com. This was the beginning of the internet.
The Advanced Research Projects Agency (ARPA) initially connected four computer network nodes. These initial computers were located at the University of California, Los Angeles; the Stanford Research Institute; U.C. Santa Barbara; and the University of Utah.
ASSY
ARPANET
there is no single person responsible for the internet. In the 1970s there was anetwork of university libraries that shared files electronically, and the concept grew and developed from there.
ARPANET.
uses of arpanet
yea ARPAnet
ARPANET was decommissioned in 1990.
ARPANET ceased to exist in 1990, so it was not around in 1996. What was around then, and what ARPANET had a part in creating, was the internet. ARPANET itself, dated back to 1969.
ARPAnet eventually developed into the World Wide Web.
ARPANET (Advanced Research Projects Agency Network) was an early packet switching network that became the technical foundation of the Internet.
IPTO orinaly created the ARPANET but several other like 'lick Licklider and Lawrence Roberts helped too
ARPANET was original name of the computer network that eventually morphed into the Internet.