
James Madison’s friendship with Thomas Jefferson was one of the longest and richest relationships of the two men’s lives. They first met in October 1776, when both were members of the Virginia House of Delegates and served on the Committee on Religion. Then just twenty-five, Madison was eight years younger than Jefferson and admired his more experienced colleague. When Jefferson was inaugurated as Governor in 1779, Madison served on the Governor’s Council, the two men had daily discussions and became close friends.
Madison and Jefferson shared many common interests. They had similar outlooks on American government, and believed that it should be looked at as a great experiment and that the principles of ancient republics would work in the US government as well. Both men loved books and were intellectually curious. Both used scientific approaches to farm their plantations, and they hired the same craftsmen to work on their homes.
From 1784 to 1789, when Jefferson served in France as commissioner and U.S. minister, he and Madison exchanged over 100 letters. In their correspondence, they discussed mutual friends, scientific investigations, and political events. They even used a cypher or code to discuss sensitive topics. Madison recommended schools for Jefferson’s nephews. Jefferson purchased books, prints, a watch, and a pedometer on Madison’s behalf. In one of the letters, Madison thanked Jefferson for the receipt of two trunks of books. He wrote: “The literary cargo for which I am so much indebted to your friendship ... is perfectly to my mind.”
One of the topics of their correspondence was the Constitutional Convention that Madison was a part of. After the Convention closed, Madison confided to Jefferson that he was disappointed that the national government would have no executive veto power over state laws.
During George Washington’s administration, Jefferson was Secretary of State and Madison was a leading member of the House of Representatives. A rift developed between Washington, who wanted a strong central government and Madison and Jefferson, who the liberty of the individual. This split led to the development of the Federalist and Republican political parties.
When Jefferson became president in 1801, his natural choice for Secretary of State was James Madison. Madison and Jefferson ignored their "strict construction" view of the Constitution to take advantage of the opportunity presented by the Louisiana Purcjase. Jefferson would have preferred to have a constitutional amendment authorizing the purchase, but gave in to expediency over formality. Madison and Jefferson had also decided on an embargo to punish Britain and France for their refusal to acknowledge American sovereignty at sea. The embargo forbade American trade with any foreign nation. The embargo failed in the United States and caused massive hardships for sellers of American products. The Federalists made a comeback in the Northeast by attacking the embargo, which was allowed to expire just as Jefferson was leaving office.
Even in retirement, Madison continued to be what Jefferson called his “pillar of support.” Madison served on the Board of Visitors for Jefferson’s University of Virginia, and succeeded Jefferson as rector of the University after his death in 1826. A few months before Jefferson died, he wrote to Madison, telling him, “The friendship which has subsisted between us, now half a century, and the harmony of our political principles and pursuits, have been sources of constant happiness to me through that long period.” Jefferson added in closing, “Take care of me when dead, and be assured that I shall leave you with my last affections.”
Madison paid tribute to his friend shortly after Jefferson’s death, stating: “He lives and will live in the memory and gratitude of the wise and good, as a luminary of science, as a votary or liberty, as a model of patriotism, and as a benefactor of human kind. In these characters, I have known him, and not less in the virtues and charms of social life, for a period of fifty years, during which there was not an interruption or diminution of mutual confidence and cordial friendship, for a single moment in a single instance.”

The relationship between these two great men is explored in much greater detail in the 2010 book by Andrew Burstein and Nancy Isenberg entitled Madison and Jefferson.