He was one of the most effective one term Presidents in our history and that only because he declared that he wouldn't run for a second term.
He certainly wasn't perfect but unlike today, we didn't have perfect Presidents back then.
https://en.wikipedia.org/wiki/James_K._Polk
James Knox Polk (November 2, 1795 June 15, 1849) was the 11th President of the United States (18451849). Polk was born in Mecklenburg County, North Carolina.[1] He later lived in and represented Tennessee. A Democrat, Polk served as the 17th Speaker of the House of Representatives (18351839) and Governor of Tennessee (18391841). Polk was the surprise (dark horse) candidate for president in 1844, defeating Henry Clay of the rival Whig Party by promising to annex Texas. Polk was a leader of Jacksonian Democracy during the Second Party System.
Polk is often considered the last strong preCivil War president, and he is the earliest of whom surviving photographs were taken during a term in office. Many scholars and historians have commented on his interventionist foreign policy; he threatened war with the United Kingdom over the issue of which nation owned the Oregon Country, then backed away and split the ownership of the region with the UK. When Mexico rejected American annexation of Texas, Polk also led the nation to a sweeping victory in the MexicanAmerican War, which gave the United States most of its present Southwest. He secured passage of the Walker tariff of 1846, which had low rates that pleased his native South, and he established a treasury system that lasted until 1913.
Polk oversaw the opening of the U.S. Naval Academy and the Smithsonian Institution, the groundbreaking for the Washington Monument, and the issuance of the first postage stamps in the United States.
He promised to serve only one term and did not run for reelection. He died of cholera three months after his term ended.
Scholars have ranked him favorably on lists of greatest presidents for his ability to promote, obtain support for, and achieve all of the major items on his presidential agenda. Polk has been called the "least known consequential president"[2] of the United States.



Thanks for the thread, Don Viejo.