[3] His articles in the daily press attracted attention due to their energetic opposition to the Conservative government of José Ignacio de Márquez from 1837 to 1840.

After the revolution of the latter year he became editor of the Gaceta Mercantil de Santa Marta, which exercised a great influence, and paved the way for the triumph of the Partido Liberal Colombiano in the elections of 1849.

When the Liberal party lost power he returned to journalism, and, except during the short time that he was state executive for Santander, he sustained an energetic opposition to the Conservative government.

When President Mariano Ospina Rodríguez was overthrown, and the federation proclaimed by the constituent convention of Rio Negro, 4 February 1863, Murillo was appointed minister to Europe, and afterward to the United States.

After the deposition of Mosquera, 25 May 1867, Murillo was a member of the legislature of Cundinamarca, and afterward for a short time again minister to the United States and judge of the supreme court.

[3] His successor to the Presidency, Santiago Pérez de Manosalbas, although belonging to the opposite party, sent him as Envoy Extraordinary and Minister Plenipotentiary to Venezuela to arrange the pending question of boundaries according to the proposal of Guzman Blanco.