Invited to the Tammany Hall celebration of Independence Day, he wrote, on June 28, 1856, a letter in behalf of Buchanan. There was no diminution in explicit clearness; but hope was nearly gone; the peril of the Union obscured every other danger; the South was so threatening that patriotism seemed to him to require at the least a surrender to all that had passed; and for the future our best reliance would be upon a fair vote in Kansas between freedom and slavery. He could not come to its meeting, he told Tammany Hall, because of his age. He had left one invitation unanswered; and if he were so to leave another, he might be suspected of a desire to conceal his sentiments. But this letter should be his last, as it was his first, appearance in the canvass. He was glad of the Democratic reunion; for although not always perfectly right, in no other party had there been "such exclusive regard and devotion to the maintenance of human rights and the happiness and welfare of the masses of the people." There was a touch of age in his fond recitals of the long services of that party since, in Jefferson's days, it had its origin with "the root-and-branch friends of the Republican system;" of its support of the war of 1812; of its destruction of the national bank; of its establishment of an independent treasury. But slavery, he admitted, was now the living issue. Upon that he had no regrets for his course. He had always preferred the method of dealing with that institution practiced by the founders of the government. He lamented the recent departure from that method; no one was more sincerely opposed than himself to the repeal of the Missouri Compromise. He had heard of it, and condemned it in a foreign land; he had there foreseen the disastrous reopening of the slavery agitation. But the measure was now accomplished; there was no more left than to decide what was the best now to do. The Kansas-Nebraska act had, he said, gradually become less obnoxious to him; though this impression, he admitted, might result from the unanimous acquiescence in it of the party in which he had been reared. Its operation, he trusted, would be beneficial; and he had now come to believe that the feelings and opinions of the free States would be more respected under its provisions than by specific congressional interference. He did not doubt the power of Congress to enable the people of a Territory to exclude slavery. Buchanan's pledge to use the presidential power to restore harmony among the sister States could be redeemed in but one way; and that was, to secure to the actual settlers of the Territory a "full, free, and practical enjoyment" of the rights of suffrage on the slavery question conferred by the act. He praised Buchanan, if not exuberantly, still sufficiently. He must, Van Buren thought, be solicitous for his reputation in the near "evening of his life." He believed that Buchanan would redeem his pledge, and should therefore cheerfully support him. If Buchanan were elected, there were "good grounds for hope" that the Union might be saved. Such was this saddening and despondent letter. It was a defense of a vote which it was rather sorry work that he should have needed to make. But the tramp of armies and the conflagration of American institutions were heard and seen in the sky with terrifying vividness. The letter secured, however, no forgiveness from the angry South. The "Richmond Whig" said: "If there is a man within the limits of the Republic who is cordially abhorred and detested by intelligent and patriotic men of all parties at the South, that man is Martin Van Buren."
Many of the best Americans shared Van Buren's distrust of Fremont and of those who supported Fremont; they shared his love of peace and his fear of that bloodshed, North and South, which seemed the dismal El Dorado to which the "pathfinder's" feet were surely tending. So the majority of the Northern voters thought; for those north of Mason and Dixon's line who divided themselves between Buchanan and Fillmore, the candidate of the "Silver Gray" Whigs, considerably outnumbered the voters for Fremont.
In 1860 Van Buren voted for the union electoral ticket which represented in New York the combined opposition to Lincoln. Every motive which had influenced him in 1856 had now increased even more than his years. The Republican party was not only now come bringing, it seemed, the torch in full flame to light an awful conflagration; but in its second national convention there became obvious upon the tariff question the preponderance of the Whig elements, which made up the larger though not the more earnest or efficient body of its supporters.
After Van Buren's return from Europe in 1855, he lived in dignified and gracious repose. This complete and final escape from the rush about him had often seemed in his busy strenuous years full of delight. But doubtless now in the peaceful pleasures of Lindenwald and in the occasional glimpses of the more crowded social life of New York which was glad to honor him, there were the regrets and slowly dying impatience, the sense of isolation, which must at the best touch with some sadness the later and well-earned and even the best-crowned years. At this time he began writing memoirs of his life and times, which were brought down to the years 1833-1834; but they were never revised by him and have not been published. Out of this work grew a sketch of the early growth of American parties, which was edited by his sons and printed in 1867. Its pages do not exhibit the firm and logical order which was so characteristic of Van Buren's political compositions. It was rather the reminiscence of the political philosophy which had completely governed him. With some repetitions, but in an easy and interesting way, he recalled the far-reaching political differences between Jefferson and Hamilton. In these chapters of his old age are plain the profound and varied influences which had been exercised over him by the great founder of his party, and his unquenchable animosity towards "the money power" from the days of the first secretary of the treasury to its victory of "buffoonery" in 1840. In one chapter, with words rather courtly but still not to be mistaken, he condemns Buchanan for a violation of the principles of Jefferson and Jackson in accepting the Dred Scott decision as a rule of political action; and this the more because its main conclusion was unnecessary to adjudge Dred Scott's rights in that suit, and because its announcement was part of a political scheme. Chief Justice Taney and Buchanan, Van Buren pointed out, though raised to power by the Democratic party, had joined it late in life, "with opinions formed and matured in an antagonist school." Both had come from the Federalist ranks, whose political heresy Van Buren believed to be hopelessly incurable.
At the opening of the civil war Van Buren's animosity to Buchanan's behavior became more and more marked. He strongly sympathized with the uprising of the North; and sustained the early measures of Lincoln's administration. But he was not to see the dreadful but lasting and benign solution of the problem of American slavery. His life ended when the fortunes of the nation were at their darkest; when McClellan's seven days' battle from the Chickahominy to the James was just over, and the North was waiting in terror lest his troops might not return in time to save the capital. For several months he suffered from an asthmatic attack, which finally became a malignant catarrh, causing him much anguish. In the latter days of his sickness his mind wandered; but when sensible and collected he still showed a keen interest in public affairs, expressed his confidence in President Lincoln and General McClellan, and declared his faith that the rebellion would end without lasting damage to the Union.
On July 24, 1862, he died, nearly eighty years old, in the quiet summer air at Lindenwald, the noise of battle far away from his green lawns and clumps of trees. In the ancient Dutch church at Kinderhook the simple funeral was performed; and a great rustic gathering paid the last and best honor of honest and respectful grief to their old friend and neighbor. For his fame had brought its chief honor to this village of his birth, the village to which in happy ending of his earthly career he returned, and where through years of well-ordered thrift, of a gentle and friendly hospitality, and of interesting and not embittered reminiscence, he had been permitted
"To husband out life's taper at the close,
And keep the flame from wasting by repose."