This question was still pending, with a fair prospect of a decision in Adams's favor, when his speech in favor of reprisals on France, which did not correspond with the sentiment of Massachusetts, caused him to be abandoned by his supporters in the state senate, and led to the election of Davis, who had before beaten him as governor. Thus again forcibly cut loose from all party connections, Mr. Adams was left at liberty to follow the bent of his own daring and energetic spirit. The abolitionists had now begun to appear on the political stage, but in the prevailing anxiety to avoid giving offence to the South, reference was seldom made to them on the floor of congress except with disclaimers of sympathy, if not with expressions of detestation. The measure principally employed by the abolitionists at that time was the presentation of petitions for the abolition of slavery in the District of Columbia and the territories. To get rid of this importunity, congress had adopted rules which were maintained by Mr. Adams to be inconsistent with the right of petition itself. In this emergency he stepped forward as the champion and guardian of that right.

Though he had taken the position of being opposed to the legislation asked for by the abolitionists, as not seasonable or expedient for the moment, he still insisted on their right to be heard. Upon this point he fought for years a battle which drew all eyes upon him as the representative of a principle which found in him an unflinching advocate and indefatigable champion. This new and eminent position was one which Mr. Adams was perfectly adapted to fill. With an iron constitution, strengthened by an active and abstemious life, there was, during his long term of service in congress, not a single member who equalled him, notwithstanding his great age, in capacity for application and powers of endurance; certainly not one whose attendance upon the business of the house was so exact and unremitting. In acquired knowledge, whether by books or personal experience, he far surpassed any of his fellow members; and what was of greater consequence, his stores of knowledge were always at hand and ready for use.

Though his voice was weak, in consequence of which the members usually crowded about him when he spoke, he never became exhausted with fatigue; and though his manner was not pleasing and had little variety, yet the peculiar views which he took, and the copiousness and novelty of his illustrations, always held his audience in profound attention. Though he had the appearance often, especially to strangers, of speaking in a passion, at least in ill humor, and of laboring under a degree of excitement, he was in fact perfectly self-possessed, and in the midst of the storms and tumults which he raised about him never lost in the slightest degree his own self-control. We have no space to dwell on the history of his congressional career, which would fill a volume; but we must not omit to notice his defeat, in February, 1837, of his opponents on the question of a censure upon him for sending up to the speaker a petition purporting to come from slaves, as one of the most signal instances of his triumph. His undaunted bearing, his courage and determination, which no threats and no tumults could suppress, soon drew around him, as a moral aid and support, a body of external applauders and admirers; so that from this time forward he became the representative not merely of one of the districts of Massachusetts, but of a great embryo party, the party in fact of northern sentiments and ideas, a party which he himself had contributed his share toward burying under ground, but which he now labored night and day to help emerge again into life.

Nor did Mr. Adams confine his labors on this question to congress. In the famous Amistad case - the case of certain newly imported Africans, who, while being transported from one port of Cuba to another, had made themselves masters of the vessel and had escaped to the coast of the United States - he appeared in the federal supreme court as counsel for the Africans, in opposition to the claim set up by their Spanish purchasers from whom they had escaped; a claim zealously urged not merely by the Spanish government, but covertly also by Mr. Van Buren, then president of the United States. Indeed, he seldom declined any occasion in his power of addressing an audience. The following may serve as a specimen: He left Boston one Monday morning to attend the opening of congress. That same evening he delivered an address before the young men's institute in Hartford, and the next evening a similar lecture before a similar institute in New Haven. On Wednesday evening he lectured before the New York lyceum; on Thursday evening he delivered an address in Brooklyn, and on Friday evening another lecture in New York, whence he proceeded next day to Washington to be present at the opening of congress on the following Monday. Though greatly engrossed by the subject of slavery, he did not confine his attention to it.

Few leading topics came before the house on which he did not speak. In the organization of the house in December, 1839, which had been delayed for four days by the persistency of the clerk in undertaking to reject certain members from New Jersey who had certificates of election, but as the clerk thought improperly granted, Mr. Adams finally intervened with great energy and effect, and to general satisfaction. It was chiefly through his activity and perseverance that the Smithsonian institution was organized. In 1845 the obnoxious "gag rule," originally enacted in 1836, was rescinded, and from that moment Mr. Adams somewhat relaxed his zeal and labors. He began, indeed, to feel at last the effects of age. His health had been somewhat shaken by a heavy fall in the house of representatives, caused by his foot catching in the floor matting, by which his shoulder was dislocated and a severe contusion inflicted on his forehead. It rendered him for the moment insensible, and though it did not prevent his appearance the next day in his seat, he suffered permanently from it. On Nov. 20, 1846, just as he was about to leave Boston for Washington, he experienced a shock of paralysis which kept him from his seat for the next four months. After this he attended congress regularly, but seldom spoke.