Amnesty International (AI), an international human rights non-governmental organization (NGO), was founded in London by Peter Benenson in 1961. Benenson, a lawyer, had become concerned about the case of two students imprisoned in Portugal for toasting to freedom in a bar. He published an article in the London Observer on the case on May 28, 1961, and advocated the writing of letters to the Portuguese government demanding the release of the students. The response was extraordinary. The article was translated and reprinted internationally, and readers began sending letters and support not only to Benenson, but also to prisons and labor camps worldwide.

In July 1961, an international group of delegates met and decided to establish "a permanent international movement in defense of freedom of opinion and religion." Shortly thereafter, an office and library was established in London, staffed by volunteers. Affiliated letter-writing groups were initially established in the United Kingdom, West Germany, Holland, France, Italy, and Switzerland, and expanded the following year to Norway, Sweden, Demark, Belgium, Greece, Australia, Ireland and the United States. By the end of 1962, 210 prisoners had been adopted by 70 groups in 7 countries, and Amnesty International had sent missions to Ghana, Czechoslovakia, Portugal and East Germany. By 1970, the organization had expanded to 850 groups in 27 countries.

As the organization grew, a Research Bureau and the International Secretariat -- the central office that serves as the headquarters of the international organization -- were formally established in London in 1963. That same year, the International Executive Committee (IEC), which has overall responsibility for AI's affairs, was established under the aegis of Sean MacBride, an Irish human rights advocate. National organizational structures, or sections, were also established to coordinate work within countries under the leadership of the headquarters in London. The United States section (known as Amnesty International of the USA, Inc. or AIUSA), the largest in the organization, was incorporated in 1966.

The National Office was the United States section's main professional office until approximately the early 1970s. Additional regional and program offices were established throughout the 1970s and early 1980s. Prior to 1981, the board of directors handled much of the daily administration of the section. After this time, the presence of an established professional structure allowed the board to focus more exclusively on policy issues. This expansion, professionalization, and a push for decentralization during the 1980s by allowed for the management of the section's work to expand beyond the National Office. The work of the section is carried out through the national office, regional offices, networks, country specialists (formerly known as country coordination groups or co-groups), student groups, and local groups. In addition, as the budget of the International Secretariat is financed by assessments on the national sections, AIUSA, as the largest section, provides a significant portion of the International Secretariat's budget.

In its early years, the main focus of Amnesty International's campaigns was to free prisoners of conscience. Within a short time, the organization's mandate expanded to include campaigning for prompt and fair trails for all political prisoners, to end extrajudicial executions and disappearances, and to abolish the death penalty, torture and other cruel treatment or punishment. The organization has always worked to bring perpetrators of these abuses to justice in accordance with international standards. Amnesty International was awarded the Nobel Peace Prize for its work in 1977.

Amnesty International underwent tremendous growth during the 1980s. By 1985, there were 3,433 groups in 50 countries, and over 500,000 members. The organization also used music concerts to raise its profile and the awareness of human rights issues. In 1986, AIUSA organized the Conspiracy of Hope Tour in the United States, which included U2, Sting, Peter Gabriel, Bryan Adams, Lou Reed, the Neville Brothers. In 1988, Amnesty International organized Human Rights Now! This tour, which coincided with the 40th anniversary of the United Nations' Universal Declaration of Human Rights, went to 19 cities in 15 countries and was broadcast live on Human Rights Day. By 1990, Amnesty International had 700,000 members and over 6,000 groups in 70 countries.

Today, Amnesty International has over 2 million members, supports and subscribers in over 150 countries.