Along with
Caesar Augustus Rodney and
John Graham, Bland was selected by President
James Monroe in November 1817 for a special diplomatic mission to
South America, the
South American Commission of 1817–1818. He was endorsed for the slot by the secretary to the commission,
Henry Marie Brackenridge. Bland suggested to Monroe that at least part of the Commission be authorized to visit
Chile and authorization for this was given by
United States Secretary of State John Quincy Adams two-weeks before setting sail. Under the command of Commodore
Arthur Sinclair, the sailed on December 4, 1817, and arrived at
Rio de Janeiro on January 29, 1818. In
Montevideo, Bland introduced
botanist William Baldwin, who accompanied the commission as the
ship's surgeon, to exiled Chilean general
José Miguel Carrera. In April, Bland left
Buenos Aires and went overland to
Mendoza,
Argentina then across the
Uspallata Pass to
Santiago, Chile. Meanwhile, the rest of the group departed the
Isla Margarita on June 25, 1818, and returned to
Norfolk, Virginia on July 8. A week later, Bland left
Valparaíso and arrived in
Philadelphia,
Pennsylvania, on October 29, 1818. The findings of the commissioners differed widely so much that they offered independent statements rather than one joint statement. Regarding the
Government of Buenos Ayres, Secretary of State Adams summarized in his memoirs that "Bland holds them in abhorrence and contempt". Unlike the reports of the others who commented nearly only on political, military, and commercial matters, Bland's were longer and provided more discussion on geography and agriculture. He was impressed by the agricultural possibilities of Chile. The protagonists of the South American trip were all given "positions of trust" after their return. ==Federal judicial service==