As the war clouds began to gather for the coming Revolution, Adams remained a simple man living in poverty–little made him stand out in a crowd. He lived with his two children from his first wife, one slave, a Newfoundland dog, and his second wife, Elizabeth Welles. Welles, whom he wed in 1764, ran the family finances and had enough business sense to keep the family out of the poor house. Together, they oversaw the pious household: grace was said before every meal, and Bible passages were read at night.

In June 1767, Adams's financial problems as tax collector came to a head. The city brought suit against him, and an appeal court ruled that he should pay the full amount, beginning with a payment of 1,463 pounds nine months hence. In March 1768, he appeared with a petition seeking more time, and, after a hot debate at a town meeting, he was given an additional six months. In 1769, when the matter came up yet again, Adams had grown so popular that he was able to shift the burden of tax collection to another man and wean himself of the entire matter.

Meanwhile, anti-Tory sentiment had continued to grow in Boston. Adams had created a "black list" of Tories and published it in the Boston Gazette; he demanded that votes in the Massachusetts House be recorded by name, and the Tories who opposed Adams's men found their names publicly announced. While Governor Bernard tried to counter by throwing patriots out of appointed government offices like militia posts, the effort backfired, and the opposition picked up nineteen seats in the House–exclusively at the cost of "black- listed" Tories. Adams rose in the newly patriotic assembly to Clerk while his friend James Otis became speaker. Adams oversaw the removal from the Massachusetts Council of six supporters of Governor Francis Bernard, the colony's highest governing body. The government–led by one crown-appointed governor and a popularly-elected assembly–was beginning to show signs of wear. Adams and Otis even were able to remove their long-time nemesis, Thomas Hutchinson.

A political change in Britain brought Charles Townshend to power as the Chancellor of the Exchequer. Townshend seized upon a nuance of the colonists' earlier protests to put in place a system of taxation they could not fight. Earlier, during the Stamp Act controversy, the colonists had argued that Britain did not have the right to post "internal" taxes like the Stamp Act but that its power was limited to "external" taxes like import duties. Townshend quickly passed a series of import duties, reestablishing the dreaded writs and establishing the customs headquarters in Boston in an effort, largely, to spite the colonists. Bostonians reacted angrily to the new laws. They saw the new rules and new officials as even more ominous than the dreaded Sugar Act and Stamp Act. Adams hatched a plan to seize the new officials when they landed in Boston–marching them to the Liberty Tree and forcing them to chose between resigning their offices or be given over to the mob. Otis and some others, however, blocked Adams, and Adams set about trying to provoke a conflict some other way. The new commissioners proved to be everything the colonists had feared, and tensions mounted as the new taxes were heavily enforced.

In the winter of 1767, the House of Representatives sent a protest letter to the king. However, another plan of Adams's–to send a circular letter to the other colonies explaining their current tribulations–was soundly defeated, as few representatives wanted to directly bring down the wrath of Britain. As the session wound down, many of the Tory supporters from western Massachusetts headed back to their farms, leaving Adams's men in the majority. He seized the opportunity to reconsider the circular letter and after two weeks of careful debate, the House agreed. The letter denied Britain's right to "external taxes" and the government. Britain demanded the House retract the letter and sent another circular letter to the colonies demanding they ignore Massachusetts's missive. The original letter, coupled by Britain's response, helped send patriotic fervor to a new level in the colonies.

It became increasingly clear to the British custom agents that they were able to collect custom duties only because Sam Adams allowed them. At night, their homes were often surrounded by chanting Sons of Liberty, and the "controlled mobs" of Boston were itching for the chance to attack. They realized that their only hope of long-term survival was with the protection of British troops. A riot on June 10, 1768 convinced the British government to send two regiments to Boston. Throughout the summer, anti-British sentiment grew. Adams argued that any British troops should be regarded as a foreign enemy. On September 3, Governor Bernard mentioned to one councilman that troops would be arriving soon, and, by the next day, all of Boston was up in arms over the coming "invasion."

On September 12, 1768, Adams and Bernard came face-to-face at a town meeting. Adams and Otis demanded that Bernard summon the General Court and argued that no standing army could be quartered in the area without the express consent of the Court. Soon, though, it became clear that such a summons would only come once the troops had arrived. Thus Adams and his Sons of Liberty began planning a colony-wide convention, which they hoped would send war fever throughout Massachusetts. On September 19–three days before the planned convention–Bernard publicized the orders for a thousand troops from Halifax and Ireland. And Adams's much-heralded convention turned out to be little more than another meeting of conservative farmers, who considered themselves just audacious enough to possibly send another petition to the king. When reports came of British naval ships appearing off the coast, the convention quietly broke up and faded away. The troops arrived unheeded, and the Sons of Liberty became the laughingstock of the colony. However, the significance of the convention is easily missed: it represented the first extra-legal institution Adams had created and had threatened to overturn the British government in one fell swoop. And any such bickering between the country farmers and the city merchants quickly fell by the wayside as British redcoats marched into town. This would soon be war.