The US government has relaxed its control over how the internet is run.
It has signed a four-page "affirmation of commitments" with the net regulator Icann, giving the body autonomy for the first time.
Previous agreements gave the US close oversight of Icann - drawing criticism from other countries and groups.
The new agreement comes into effect on 1 October, exactly 40 years since the first two computers were connected on the prototype of the net.
"It's a beautifully historic day," Rod Beckstrom, Icann's head, told BBC News.
The European Commission, which has long been critical of Icann's alliance with the US government, welcomed the new deal.
"Internet users worldwide can now anticipate that Icann's decisions...will be more independent and more accountable, taking into account everyone's interests," said Viviane Reding, European Commissioner for information society and media.
The Internet Corporation for Assigned Names and Numbers (Icann) is a not-for-profit private sector corporation - set up by the US government - to oversee critical parts of the internet, such as the top-level domain (TLD) name system. Top level domains include .com and .uk.
Since its inception in 1998, it has periodically signed accords - known collectively as the Joint Project Agreement (JPA) - with the US Commerce Department's National Telecommunications and Information Administration.
These papers meant that the US government was responsible for reviewing the work of the body.
These have now been abandoned in favour of the new "affirmation of commitments", a brief document which turns the review process over to the global "internet community".
"Under the JPA, Icann staff would conduct reviews and hand them over to the US government," explained Mr Beckstrom.
"Now we submit those reviews to the world and post them publically for all to comment."
In addition, independent review panels - including representatives of foreign governments - would specifically oversee Icann's work in three specific areas: security, competition and accountability.
The US will retain a permanent seat on the accountability panel.
Mr Beckstrom said the decision to break away from the US government in all other areas had been made "over the last year and a half".
"Stakeholders told us that the JPA should not be renewed and that it wasn't appropriate for it to be renewed," he told BBC News.
"It is also recognition by the US government that the internet is a global system."
The internet began as a research project by the US military, known as Arpanet.
On 1 October 1969, the second computer was connected to the network, said Mr Beckstrom. Ever since, the US has paid close attention to the workings and growth of the net.
"Today's announcement bolsters the long-term viability of the internet as a force for innovation, economic growth, and freedom of expression," said US Assistant Secretary for communications and information Lawrence Strickling.
"This framework puts the public interest front and centre."
Businesses have also welcomed the change of direction by the US.
"Google and its users depend every day on a vibrant and expanding internet; we endorse this affirmation and applaud the maturing of Icann's role in the provision of internet stability," said Eric Schmidt, CEO of Google.
However, the new agreement does not totally sever the links between the US government and Icann entirely.
In addition, Icann also has a separate agreement with the US - to run the Internet Assigned Numbers Authority (IANA) - that expires in 2011.
The IANA oversees the net's addressing system.