Zachary Taylor was a major general who served as the 12th president of the United States from March 1849 until his death in July 1850.

His success in the Second Seminole War, especially the Battle of Lake Okeechobee, attracted national attention and earned him the nickname "Old Rough and Ready".

In July 1811 he was called to the Indiana Territory, where he assumed control of Fort Knox after the previous commandant fled due to rising tensions between Governor William Henry Harrison and the Shawnee chief Tecumseh. In a few weeks, Taylor was able to restore order in the garrison, for which he was lauded by Governor Harrison.

During the Black Hawk War, Taylor opposed the engagement of his 17-year-old daughter Sarah Knox Taylor to Lieutenant Jefferson Davis, the future President of the Confederate States of America. He did not wish his daughter to become a military wife, as he knew it was a difficult life. Nevertheless, Davis and Sarah Taylor married in June 1835 (when she was 21). She died three months later of malaria contracted on a visit to Davis' sister's home in St. Francisville, Louisiana.

The Mexican-American War broke out in April 1846, and Taylor defeated Mexican troops commanded by General Mariano Arista at the battles of Palo Alto and Resaca de la Palma and drove his troops out of Texas. Taylor then led his troops into Mexico, where they defeated Mexican troops commanded by Pedro de Ampudia at the Battle of Monterrey. Defying orders, Taylor led his troops further south and, despite being severely outnumbered, dealt a crushing blow to Mexican forces under Antonio López de Santa Anna at the Battle of Buena Vista. He received three Congressional Gold Medals for his service and remains the only person to have received the medal three times.

Lt. Taylor, aged 25, married Margaret "Peggy" Smith, aged 21, on June 21, 1810, at the home of the bride's sister, Mrs. Mary Chew, near Louisville, Kentucky. Their marriage appears to have been a happy one. A devout Episcopalian, Mrs. Taylor prayed regularly for her soldier husband. She became somewhat reclusive because, it is said, she had promised God to give up the pleasures of society if her husband returned safely from war.

In his capacity as a career military officer, Taylor had never publicly revealed his political beliefs before 1848 nor voted before that time. Nevertheless, the Whig Party convinced the reluctant war hero to lead their ticket in the 1848 presidential election, hoping to replicate the success of the party's only successful presidential candidate, William Henry Harrison.

Taylor defeated Democrat Lewis Cass and Free Soil Party candidate Martin Van Buren, taking 163 of the 290 electoral votes. In the popular vote, he took 47.3%, while Cass won 42.5% and Van Buren won 10.1%. Taylor would be the last Whig to be elected president and the last person elected to the U.S. presidency from neither the Democratic Party nor the Republican Party, as well as the last Southerner to win a presidential election until Woodrow Wilson's election in 1912.

President Taylor brought his favorite steed with him to the White House in 1849, by which time "Old Whitey" really was old and spent most of his time grazing lazily on the lawn. However, he may have been too famous for his own good, as visitors to the presidential mansion were known to sometimes pull a hair or two from the horse's tail for a souvenir.

Taylor's vice president was Millard Fillmore, a prominent New York Whig who had chaired the House Ways and Means Committee and had been a contender for Henry Clay's vice presidential nominee in the 1844 election. Fillmore's selection was largely an attempt at reconciliation with northern Whigs, who were furious at the nomination of a slave-owning southerner for president.