Never underestimate the influence of a First Lady of the United States in world affairs. The new history Abraham Lincoln and Mexico reveals the role of Mary Todd Lincoln in furthering foreign relations with Mexico, based in part on archival documents in both the USA and Mexico.
Mrs. Lincoln had many meetings and shopping trips with the Mexican consul in Washington, Matias Romero, during which she shared his anxiety over France having an army in Mexico and the danger of it joining up with the Confederacy. Based on their mutual concerns, she urged President Lincoln to support Mexico in the 1860s. What particularly endeared the American President to Romero was the fact the consul escorted Mrs. Lincoln on her frequent shopping trips in the capital with good-natured grace. It was a duty which Lincoln was happy to relinquish.
Romero, in his voluminous notes and correspondence (now part of the archives of Banco Nacional de México), was the first to note the similarities between Lincoln and Benito Juárez. Lincoln befriended the twenty-four-year-old diplomat, and their friendship would last his lifetime. Also, Lincoln promised that his administration would treat Mexico fairly. Romero, who knew of Lincoln’s anti-expansionist views, promised in turn that Juárez would pursue liberal policies and be friendly to American investments.
As a result, the Lincoln administration furnished massive amounts of military weapons to Mexico as the US Civil War was ending, and Union officers and troops redeployed to Mexico to help defeat the Imperial Army of Napoleon after Lincoln’s death.