quality:correction
Member of Continental Congress

In 1774, at the instigation of Samuel Adams, the First Continental Congress was convened in response to the Intolerable Acts, a series of deeply unpopular measures intended to punish Massachusetts, centralize authority in Britain, and prevent rebellion in other colonies. Four delegates were chosen by the Massachusetts legislature, including John Adams, who agreed to attend, despite an emotional plea from his friend, Attorney General Jonathan Sewall, not to.

Shortly after he arrived in Philadelphia, Adams was placed on the 23-member Grand Committee tasked with drafting a letter of grievances to King George III. The committee soon split into conservative and radical factions. Although the Massachusetts delegation was largely passive, Adams criticized conservatives such as Joseph Galloway, James Duane, and Peter Oliver who advocated a conciliatory policy towards the British or felt that the colonies had a duty to remain loyal to Britain, although his views at the time aligned with those of conservative John Dickinson. Adams sought the repeal of objectionable policies, but at this stage he continued to see benefits in maintaining the ties with Britain. He renewed his push for the right to a jury trial. He complained of what he considered the pretentiousness of the other delegates, writing to Abigail, "I believe if it was moved and seconded that We should come to a Resolution that Three and two make five We should be entertained with Logick and Rhetorick, Law, History, Politicks and Mathematicks, concerning the Subject for two whole Days, and then We should pass the Resolution unanimously in the Affirmative." Adams ultimately helped engineer a compromise between the conservatives and the radicals. The Congress disbanded in October after sending the petition to the King and showing its displeasure with the Intolerable Acts by endorsing the Suffolk Resolves, which called for a boycott of British goods.

Adams's absence was hard on Abigail, who was left alone to care for the family. She still encouraged her husband in his task, writing: "You cannot be, I know, nor do I wish to see you an inactive Spectator, but if the Sword be drawn I bid adieu to all domestick felicity, and look forward to that Country where there is neither wars nor rumors of War in a firm belief that thro the mercy of its King we shall both rejoice there together."

News of the opening hostilities with the British at the Battles of Lexington and Concord made Adams hope that independence would soon become a reality. Three days after the battle, he rode into a militia camp and, while reflecting positively on the high spirits of the men, was distressed by their poor condition and lack of discipline. A month later, Adams returned to Philadelphia for the Second Continental Congress as the leader of the Massachusetts delegation. He moved cautiously at first, noting that the Congress was divided between Loyalists, those favoring independence, and those hesitant to take any position. He became convinced that Congress was moving in the proper direction – away from Great Britain. Publicly, Adams supported "reconciliation if practicable," but privately agreed with Benjamin Franklin 's confidential observation that independence was inevitable.

In June 1775, with a view of promoting union among the colonies against Great Britain, he nominated George Washington of Virginia as commander-in-chief of the army then assembled around Boston. He praised Washington's "skill and experience" as well as his "excellent universal character." Adams opposed various attempts, including the Olive Branch Petition, aimed at finding peace. Invoking the already-long list of British actions against the colonies, he wrote, "In my opinion Powder and Artillery are the most efficacious, Sure, and infallibly conciliatory Measures We can adopt." After his failure to prevent the petition from being enacted, he wrote a private letter derisively referring to Dickinson as a "piddling genius." The letter was intercepted and published in Loyalist newspapers. The well-respected Dickinson refused to greet Adams and he was for a time largely ostracized. Ferling writes, "By the fall of 1775 no one in Congress labored more ardently than Adams to hasten the day when America would be separate from Great Britain." In October 1775, Adams was appointed chief judge of the Massachusetts Superior Court, but he never served, and resigned in February 1777. In response to queries from other delegates, Adams wrote the 1776 pamphlet Thoughts on Government, which laid out an influential framework for republican constitutions.