The Iran hostage crisis occurred when Mohammed Reza Pahlavi, a domineering Iranian ruler who was recently expelled from his country, was granted access into the United States by President Jimmy Carter to receive cancer treatment. This caused an outrage in Iran, leading many Iranian citizens to feel greatly betrayed by the country that once supported them. Iran's Islamic citizens eventually stormed the U.S. embassy, holding 66 Americans hostage.
The Iran hostage crisis started Nov. 4, 1979, and it ended on Jan. 20, 1981, lasting 444 days, according to History.com and PBS. President Carter's acceptance of Pahlavi into America caused Iranians to conclude that the United States greatly supported Pahlavi despite him being overthrown as their leader. This caused bitter relations between the United States and Iran, and it also caused many Iranians to have strong feelings of contempt for President Carter.
Between the start and end of the Iran hostage crisis, 14 hostages were released. The African-American and women hostages were released on Nov. 19 and 20 in 1979, and one hostage was released in July 1980 due to illness. The remaining 52 hostages were held captive until Ronald Reagan was officially sworn in as president on Jan. 20, 1981.