On 26 October 1774 the Continental Congress adjourned, and its members returned home. John Adams left Philadelphia on the 28th, arriving in Braintree probably on 9 November (Diary and Autobiography description begins Diary and Autobiography of John Adams, ed. L. H. Butterfield and others, Cambridge, 1961; 4 vols. description ends , 2:157–160). In his passage through Massachusetts, he was informed of the actions of the Provincial Congress, which had begun meeting on 7 October in Salem, after the dismissal of the General Court by General Gage, and had moved to Concord on 11 October and to Cambridge on the 17th. It adjourned on the 29th, to reconvene on 23 November.

When the Provincial Congress reassembled in November, the Massachusetts delegates to the Continental Congress who were also members of the Provincial Congress were appointed to the Committee on the State of the Province. At the same time resolutions were passed requesting the presence of Robert Treat Paine and John Adams, not yet chosen by Braintree as one of its representatives to the Provincial Congress—an indication that he was still in Braintree, but that Samuel Adams and Thomas Cushing had arrived at the congress (Mass. Provincial Congress, Jours. description begins William Lincoln, ed., The Journals of Each Provincial Congress of Massachusetts in 1774 and 1775, and of the Committee of Safety, Boston, 1838. description ends , p. 49). On 28 November, Braintree added John Adams to its representation (Braintree Town Records description begins Samuel A. Bates, ed., Records of the Town of Braintree, 1640 to 1793, Randolph, Mass., 1886. description ends , p. 453), but he does not seem to have attended until at least 5 December, when the congress resolved that “John Adams, Esq. be joined to the committee on the state of the province” (Mass. Provincial Congress, Jours. description begins William Lincoln, ed., The Journals of Each Provincial Congress of Massachusetts in 1774 and 1775, and of the Committee of Safety, Boston, 1838. description ends , p. 58). On 2 December, Adams had been elected by the Provincial Congress to a seat in the Second Continental Congress, along with John Hancock, Thomas Cushing, Samuel Adams, and Robert Treat Paine. Their election was made official in the resolves of the congress of 5 December accepting the bill of rights, the statement of grievances, and the Association (same, p. 55, 56–58).

John Adams’ first active role in the congress was probably his membership on the committee which reported on 7 December and was charged with drafting a resolve on the “taking the number of inhabitants, and the quantity of exports and imports of merchandize and of the manufactures of all kinds in this colony,” designed for the use of the delegates to the Second Continental Congress (same, p. 61). Reporting the same morning it was appointed, this committee recommended that a committee composed of a member from each county and maritime town be named for the purpose (same, p. 61–62). John Adams was not a member of this large committee, nor does his name appear again in the journal; thus, the extent to which he was active is not certain. His presence on the Committee on the State of the Province suggests that he may have had some role in the writing of two reports of that committee: an address to the inhabitants of the province, and a report on assuming civil government. Both were issued on the last day of the first congress, 10 December.