Van Buren viewed Texas annexation as an immense political liability that would empower the anti-slavery northern Whig opposition -- especially if annexation provoked a war with Mexico. Presented with a formal annexation proposal from Texas minister Memucan Hunt, Jr. in August 1837, Van Buren summarily rejected it.

Van Buren vetoed only one bill during his administration--a measure intended to provide for the distribution of the Madison Papers.

For the first half of his presidency, Van Buren, who had been a widower for many years, did not have a specific person fill the role of White House hostess at social events, but tried to assume such duties himself. When his eldest son Abraham Van Buren married Angelica Singleton in 1838, he quickly acted to install his daughter-in-law as his hostess. She solicited the advice of her distant relative, Dolley Madison, who had moved back to Washington after her husband's death, and soon the president's parties livened up.

"Old Kinderhook" was a reference to the village of Van Buren's birth in upstate New York. The term of endearment was utilized during the 1840 election by his supporters as they formed the OK Club and marched with placards marked OK. The Oxford English Dictionary notes that the abbreviation came into great usage at the time and its popularity can be attributed to Van Buren and his supporters.

Campaigning with the slogan "Rumpsey Dumpsey, Rumpsey Dumpsey, Colonel Johnson killed Tecumseh", Richard Mentor Johnson fell one short of the electoral votes needed to secure his election and became the only vice president elected by the United States Senate under the provisions of the Twelfth Amendment. Johnson also represented Kentucky in the U.S. House of Representatives and Senate.

Van Buren appointed two Associate Justices to the Supreme Court: John McKinley, confirmed September 25, 1837, and Peter Vivian Daniel, confirmed March 2, 1841. He also appointed eight other federal judges, all to United States district courts.

In 1840, a surge of new voters -- who nicknamed him "Martin Van Ruin" -- helped turn Van Buren out of office in favor of war hero William Henry Harrison.

At a convention held in Buffalo, New York in August 1848, a group of anti-slavery Democrats, Whigs, and members of the abolitionist Liberty Party met in the first national convention of what became known as the Free Soil Party, unanimously nominating the former president as their candidate in the upcoming election. Nationwide, Van Buren won 10.1% of the popular vote, the strongest showing by a third party presidential nominee up to that point in U.S. history.