García Hamilton was born in San Miguel de Tucumán to Lucía Elena Aráoz and Enrique García Hamilton. He studied at the National University of Tucumán, graduating in 1969, and received his PhD in Legal and Social Sciences from the University of Buenos Aires, where he later was a Professor of history and law. He worked as a columnist and Secretary General of La Gaceta newspaper in Tucumán - which was owned by his family and edited by his father. He founded El Pueblo, a local newspaper, in 1972, and was named director of the Association of Provincial Newspapers; his brother, Eduardo, was also a prominent Tucumán journalist, serving as director of La Gaceta, and founder of Siglo XXI. In the mid-1970s, in the final months of the Presidency of Isabel Martínez de Perón, he was imprisoned by the government. He was a columnist for newspapers and magazines in Argentina, Uruguay and the United States. In 1975, after his release from prison and exile to Buenos Aires, García Hamilton initiated his career as a lawyer and founded García Hamilton & Asociados law firm. The firm has grown since then to become an advisory firm providing legal, tax and finance advisory services, and is now run by his sons. García Hamilton was the author of numerous books, including Hispano-American authoritarianism and unproductiveness, and biographies of Juan Bautista Alberdi, Life of an absentee ; Domingo Faustino Sarmiento, Rowdy Cuyano, and José de San Martín, Don José. Don José sold over 60,000 copies in Argentina. He won the Merit Diploma from the Konex Foundation for Life of an Absentee. He has presented several television programmes on Argentine history. In 2006, he was deported from Cuba without explanation. García Hamilton suggested that his ongoing interest in the subject of authoritarianism in Latin American politics might have been responsible. In 1991 García Hamilton ran as a candidate for vice-governor of Tucumán Province. In 2007 he was elected a national deputy for the province in support of the presidential bid of Roberto Lavagna. He later spoke out against Lavagna's return to the Kirchnerist fold. He was vice-president of the interfaith NGO Casa Argentina en Jerusalem. In 2002, García Hamilton was awarded with the , and in February 2010, the issued a commemorative set of post stamps in his memory, to remember his dedication to interfaith dialogue and tolerance. He was married to Graciela Gass, with whom he had six children. He died on 18 June 2009 after a ten-year-long battle with cancer.
