Jefferson's rise through Virginia's politics reached its apogee on 1 June 1779, when he was elected the state's second governor. It was the fulfillment of everything a classical statesman could want. Jefferson had the respect of his peers and the chance to lead his own community, all while living in his own home, able to go on living his private life. He saw it not just as validation of his work, but as a chance to put his political ideas into practice, and to show the world what good government could mean.
Unfortunately for Jefferson, he happened to take office in the worst possible circumstance for trying out novel political ideas: the middle of a war. When Jefferson assumed the governorship, the American colonists were several years deep into their revolutionary conflict with Britain, and things were not going well. Virginia hadn't yet been attacked by Redcoat soldiers, but it was a prime target and one almost completely undefended. Any other governor might have raised an army, but not Thomas Jefferson; his ideals forbade him. It was part of his understanding of a democratic people that they would spontaneously act in their own defense in times of danger. This was their country; if they loved it enough to get together in times of peace, why wouldn't they get together in times of war?
Unfortunately Jefferson's vision of democratic self-defense worked better in the abstract than in reality. In the winter of 1781, a British army under the command of turncoat general Benedict Arnold invaded Virginia, forcing the government to flee from the new capital of Richmond. In the Spring, Lord Charles Cornwallis launched a repeat of Arnold's assault, forcing Jefferson to flee again. Jefferson was bewildered, unable to understand why the people hadn't risen to their own defense. Exhausted and confused, he declined to seek reelection after his second one-year term ended. He went home the very day his tenure expired, on 4 June 1781, even before a replacement had been elected, leaving Virginia with no executive in wartime for more than a week.
After he finished his term as governor, Jefferson was ready to retire from public life. Like Cincinnatus, he wanted to get home to his farm. He crowed to friends around the country that he was done with politics for good, and he probably meant it. It isn't difficult to imagine an alternate universe in which Jefferson went home in 1781 and never left again.
But as happened so many times in Jefferson's life, historical circumstances intervened. In August 1782, Martha Jefferson gave birth to her sixth child. The pregnancy, like all of her prior pregnancies, had been difficult, and after giving birth Martha fell terribly ill. She never recovered. On 6 September 1782, Martha Jefferson passed away. Jefferson was destroyed. His older daughter Patsy recalled that he wandered around the grounds of Monticello aimlessly, babbling under his breath. On her deathbed, Martha had started to copy out a passage of Tristram Shandy but had been too weak to finish it. Jefferson completed it in his own hand. He kept the passage—half in his handwriting, half in hers—and a lock of her hair with him for the rest of his life.
Jefferson's friends in Congress had never believed in his retirement, and pressured him to return to national politics. After Martha's death they offered him the chance to go to Europe with John Adams and Benjamin Franklin to negotiate foreign treaties. Jefferson, who had rejected all prior assignments, made an abrupt about-face, and left for Europe immediately. He needed to get out Virginia. In 1785, the aging Franklin retired from the Foreign Service, and Jefferson became America's minister plenipotentiary to France. It was as far away as he could get from Monticello. And Jefferson loved it.
Jefferson's primary responsibility in Europe was to manage the United States' massive international debt. During the Revolutionary War, the various states and Congress had taken out large loans to finance the fight with Britain. Now those loans were coming due, and Jefferson had to nail down the terms with America's European creditors. This was much harder to do than you might think: under the Articles of Confederation, then governing the United States, the national government had very little power—so little that it could not even raise enough revenue to service its debts. European bankers laughed Jefferson out of their offices; what kind of a country could not even raise its own revenues reliably?
The bankers' objections helped force Jefferson to rethink his political vision. Although a strong government might infringe upon citizens' freedoms, a very weak government could have no real international presence. Without an international presence, that government would be at the mercy of other nations' designs, and so its citizens' freedom would come under attack anyway—only from the outside this time. Government then, Jefferson came to believe, needed to be weak domestically, but strong internationally.
He got the chance to articulate this newly integrated political vision in his letters to James Madison. While Jefferson and Adams were struggling to service America's foreign debt, the other Founding Fathers were meeting in Philadelphia, trying to hammer out a new political arrangement for the nation's governance. The Articles of Confederation, it turned out, didn't work much better at home than they did overseas. James Madison, Jefferson's closest friend, led the effort to replace them. Madison and Jefferson had first met during Jefferson's second term in the Virginia legislature, where Madison shepherded parts of Jefferson's reform program through the Virginia legislature. The experience turned the pair into close confidants. Beginning in the spring of 1787, Madison wrote to Jefferson about the strong central government the Constitutional Convention was creating. Jefferson agreed with Madison on the need for a stronger central government—if his experience negotiating with foreign bankers had taught him anything, it was how badly the United States needed one—but he wanted to see more protections for the citizenry. He made his support for the new Constitution contingent upon the inclusion of a bill of rights, able to protect Americans from their own government's power. Madison, originally opposed to the idea of a bill of rights, acquiesced to Jefferson's position, helping to formulate the first ten amendments even before the Constitution was ratified.
Jefferson did not especially want to return from France, but personal circumstances forced him home. He had brought his two eldest daughters to France with him, and sent them to school in a convent. The arrangement seemed to work pretty well—Jefferson could run around Paris, indulging his expensive wine habit, while his daughters were kept safely out of trouble. Then, one day, he received a letter from the fifteen-year-old Patsy, informing him she wanted to convert to Catholicism and become a nun. Jefferson never again acted with such haste; the very next day he went to the convent and withdrew his girls from the school. He immediately began making plans to return to Virginia to place his daughters into what he thought was a more wholesome environment. A Catholic daughter was not something he was prepared for. (Jefferson was a deist, and not a particularly religious one at that. Indeed, in the vicious election of 1804, accusations of his godlessness became so ferocious that he authored a short work, The Philosophy of Jesus, intended to convince the electorate that he was not an atheist.) He would be back in Virginia as soon as he could be.