The American Civil Liberties Union won the federal case
Part of Donald Trump's temporary immigration ban for nationals of seven Middle Eastern countries has been blocked by an American court.
Lawyers from the American Civil Liberties Union have secured a ruling which stops the US from deporting refugees and visitors.
A judge has ruled that those who have already landed in the US with valid visas can be temporarily allowed to stay in the country.
The American Civil Liberties Union, which won the federal district court judgment, said the ruling proved "we are a democratic republic where the powers of government are not dictatorial".
As of Saturday night, customs and border protection officials had denied entry to more than 170 people.
Others who were about to board flights back to America had been told they cannot travel - as Homeland Security Department contacted airlines recommending that they deny boarding to certain passengers.
According to the executive order, exceptions can be made when it is in the "national interest", but one federal law enforcement official said "It's unclear at this point what the threshold of the national interest is."