The ARPANET was a research project that was communications-oriented, rather than user-oriented in design.
Nonetheless, in the summer of 1975, the ARPANET was declared "operational".
The Defense Communications Agency took control since ARPA was intended to fund advanced research.
At about this time, the first ARPANET encryption devices were deployed to support classified traffic.

The transatlantic connectivity with NORSAR and UCL later evolved into the SATNET.
The ARPANET, SATNET and PRNET were interconnected in 1977.

The ARPANET Completion Report,  published in 1981 jointly by BBN and ARPA, concludes that:
 ... it is somewhat fitting to end on the note that the ARPANET program has had a strong and direct feedback into the support and strength of computer science, from which the network, itself, sprang.
The ARPANET was a research project that was communications-oriented, rather than user-oriented in design. Nonetheless, in the summer of 1975, the ARPANET was declared "operational". The Defense Communications Agency took control since ARPA was intended to fund advanced research. At about this time, the first ARPANET encryption devices were deployed to support classified traffic.
The transatlantic connectivity with NORSAR and UCL later evolved into the SATNET. The ARPANET, SATNET and PRNET were interconnected in 1977.
The ARPANET Completion Report,  published in 1981 jointly by BBN and ARPA, concludes that:
 ... it is somewhat fitting to end on the note that the ARPANET program has had a strong and direct feedback into the support and strength of computer science, from which the network, itself, sprang.
ARPANET