In 1827 he married Soledad Soublette, the younger sister of General Carlos Soublette, with whom he had nine children.
After Bolívar's death in 1830, O'Leary disobeyed orders to burn the general's personal documents. He spent much of the rest of his life organizing them, along with writing his own very extensive memoirs (spanning thirty-four volumes) of his time fighting in the revolutionary wars with Bolívar. He died in Bogotá, Colombia. He is buried in the National Pantheon of Venezuela since 1882.
A bust and plaque honouring O'Leary were presented by the Venezuelan Government to the people of Cork and unveiled on 12 May 2010 by the Venezuelan Ambassador to Ireland, Samuel Moncada.
In 1997, the Archive of the Liberator Simón Bolívar was inscribed by UNESCO in the International Memory of the World Register and in the Regional Register for Latin America and the Caribbean in 2011.
^McNerney, Jr., Robert F. (January 1966). "Daniel Florence O'Leary, Soldier, Diplomat, and Historian". The Americas. 22 (3): 292–312. doi:10.2307/979172. JSTOR979172.
