It just so happened that Jefferson entered colonial politics at a time of tremendous unrest. In 1765, the British Parliament passed the infamous Stamp Act, which infuriated American colonists who felt Parliament did not have the right to tax them at all. Although Parliament repealed the Stamp Act, it didn't concede its right to tax. The dispute was quieted, but ultimately unresolved; it was just a matter of time before it resumed.
It wouldn't be fair to say that Jefferson was oblivious to the Stamp Act crisis, but he certainly had other things on his mind. That whole business of finding a wife was proving to be more trouble than he'd thought. You see, Jefferson was not exactly a hit with the ladies. Oh sure, he was handsome and wealthy. But he was incredibly shy, and did not really know how to talk to women. While in college he had fallen for the local beauty, Rebecca Burwell, but she rejected him outright. A few years later, he tried and failed to seduce his neighbor's wife, embarrassing himself in the process. Having a family was very important to Jefferson—it was a necessary piece of the classical statesman's ideal—but he wasn't having any luck.
Finally he caught a break; sometime in the early 1770s, he met the recently widowed Martha Skelton. No portrait of her survives, but from written descriptions we know that she was slight, pretty, and—luckily for Jefferson—into brainy guys. She was very cultured; the young couple bonded over their shared love of Tristram Shandy and flirted together while playing duets. They were married on New Year's Day, 1772.
His new family kept Jefferson busy and distracted. Within a year, Martha's father had died, doubling Jefferson's holdings in land and slaves (by then he owned about two hundred) and saddling him with massive debts. Jefferson's first daughter, Martha (known as "Patsy") was born in September 1772 while construction of the new family house at Monticello dragged on. Although Jefferson did not neglect his elected duties, between his wife, his new daughter, his dead father-in-law's debts, his land holdings, and the new home he was building for his family, he was mostly focused on his personal life.
On 16 December 1773, Jefferson was abruptly pulled out of that private world and thrust fully into politics. It was on that day that in Boston Harbor, Samuel Adams and a band of rabble-rousers protested a new British tax on tea by tossing tons of the stuff into the Charles River, in what has come to be known as the Boston Tea Party. It was a provocation designed to push colonists to take up again the fight over the Stamp Act, and the British Parliament was only too happy to oblige. It ordered the port of Boston closed, stripped Massachusetts of most of its powers of self-government, and even gave British soldiers de-facto immunity for any crimes committed while imposing order on the colonies.
These "Intolerable Acts" drove the colonists to action. Jefferson helped take the lead in crafting Virginia's response. He had been serving on a correspondence committee, which kept him up to date on developments in the other twelve colonies. When he heard about the Intolerable Acts, Jefferson called for a day of fasting to show solidarity with Massachusetts. Virginia's royal governor took the display of sympathy as a sign of insurrection (which it probably was), and promptly disbanded the House of Burgesses. Unfazed, Jefferson and his peers walked down the street to the Apollo Tavern, deciding then and there to join in the Continental Congress to coordinate the colonists' response to this British injustice.
Jefferson didn't stop with organizing a meeting though. He believed that Parliament had done nothing short of violating the colonists' basic rights as free men. Although he wasn't high-profile enough to be sent to the Congress, Jefferson wrote a pamphlet to tell Virginia's delegates what he thought they should do. A Summary View of the Rights of British America, Jefferson's first published work, purported to show how the colonial right to self-governance emerged from the depths of British history. It was widely read as a sweeping and elegant denunciation of Parliament's right to rule the colonies at all, and got people talking about the smart young radical from Virginia. You could say it gave him his revolutionary credentials. He was going to need them.