Later he moved to Uruguay, where he worked as a civil servant and later as a politician. He served as the Minister of Finance in the administration of Lorenzo Batlle from 1869 to 1872. In 1890 he was elected Senator. He served as the President of the Senate of Uruguay in 1891 and 1894.[1]
The presidential election of 1894 resulted in a political crisis. For twenty-one days (between March 1 and March 21) none of the candidates received the necessary 45 votes to become president. During this time, Stewart, president of the Senate, exercised power as President of Uruguay.
Finally, Stewart ceded the office to Juan Idiarte Borda who won the presidency with 47 votes, but who was to be assassinated while President.
He married Delfina García Vargas and had eight children with her. Duncan Stewart died in 1923, having lived through practically all of Uruguay's post-independence history.
^PRESIDENCIA DE LA ASAMBLEA GENERAL Y DEL SENADO PRESIDENCIA DE LA CAMARA DE REPRESENTANTES (October 29, 2013). "Parlamentarios Uruguayos 1830-2005"(PDF). www.parlamento.gub.uy. Archived from the original(PDF) on October 29, 2013.
^PRESIDENCIA DE LA ASAMBLEA GENERAL Y DEL SENADO PRESIDENCIA DE LA CAMARA DE REPRESENTANTES (October 29, 2013). "Parlamentarios Uruguayos 1830-2005"(PDF). www.parlamento.gub.uy. Archived from the original(PDF) on October 29, 2013.