The Berlin Crisis brought the Untied Sates and the Soviet Union at the brink of conflict. Europe helped the most by giving materials to help blockade in preventing an outright confrontation. The US wouldn't have been able to get these materials without Europe being part of NATO.
The foreign ministers of Canada and 10 Western European nations (Belgium, Denmark, France, Great Britain, Iceland, Italy, Luxembourg, the Netherlands, Norway, and Portugal) all Gathered in Washington DC to sign the North Atlantic Treaty.
The Czech Republic, Hungary, and Poland were the first former Warsaw Pact countries to gain NATO membership in 1999.
One of many events that occurred was on December 14 1995 the Dayton Peace Accords had been signed in Paris, France which had ended a terrible war that was between Bosnia and Herzegovina this was not the only reason it was a very important event as it was a special day for the security in Western Balkans.
During the year 1949 at Washington DC we have the NATO treaty being signed as it has been said this is one of the most memorable events in US history as we have this Treaty being signed