Rather than have Taylor press further south, Polk called for an invasion of central Mexico designed to capture the capital at Mexico City. To command this campaign, Polk selected General Winfield Scott and assigned him 12,000 troops. Scott sailed south and decided to land his forces at Collado Beach near the port of Veracruz. Sending his troops ashore in the US Army’s first major amphibious landing, Scott quickly laid siege to the city.

Veracruz held out for twenty days before finally surrendering. In the wake of its fall, Scott left a small garrison and quickly began marching inland with 8,500 men to escape the diseases of the coast.

On April 18, Scott encountered the 12,000-man army of General Santa Anna at the fortified heights of Cerro Gordo. Though outnumbered, Scott attacked the heights after one of his engineers, Robert E. Lee, located a mountain trail that allowed the army to flank Santa Anna’s position. Surprising the Mexicans, the Americans put them to rout inflicting 4,000 casualties, as well as killing one general and capturing five.

As Scott was achieving his victory, Commodore Matthew C. Perry and the US Navy were successfully attacking Tuxpan on the coast. Perry’s forces would later attack Tabasco in June 1847. Continuing their march inland, Scott’s army occupied Puebla in May before pushing on toward the capital. Reaching the outskirts of Mexico City, the Americans assaulted the town of Contreras on August 20, 1847, routing forces under General Gabriel Valencia.

Later that day, Scott attacked the Mexican lines at Churubusco. Fighting from behind convent walls, the Mexicans beat off repeated American assaults until their ammunition began to run out and their line was broken.

Now only five miles from Mexico City, Scott advanced to the edge of the city. On September 8, 1847, believing there to be a cannon foundry in the Molino del Rey (King’s Mills), Scott ordered General William Worth to attack and destroy any munitions that were found. After hours of heavy fighting, US forces captured the mills and destroyed the foundry equipment. The battle was one of the bloodiest of conflict with the Americans suffering 780 killed and wounded and the Mexicans 2,200.

Scott now sought to take the city, however to do so would require storming Chapultepec Castle. Perched on top of a 200 foot hill, the castle dominated the western defenses of the city. On September 12, American artillery commenced firing on the castle, ceasing only when sun set. The next morning, two columns moved out, each led by a 250-man storming party, one of which included a contingent of US Marines. After a delay waiting for ladders, the American troops swarmed over the walls of Chapultepec, driving back the Mexican defenders. The first to reach the top of the wall was George Pickett, later to achieve fame in the Civil War.

As US troops poured into the castle, the Mexicans fled back the gates of the city. Pursued by Scott’s men, their resistance stiffened around the Belén and San Cosmé Gates. Led by the Mounted Rifles from General John Quitman’s division, American troops breached the Belén Gate around 1:20. The fighting around San Cosmé lasted until 6:00, when, with the aid of a howitzer commanded by Lt. Ulysses S. Grant, the gate was taken. After a long day of fighting, Scott had accomplished his mission. In doing so, he had won six battles, usually against larger forces, while operating exclusively in hostile country. Scott’s success was such that his campaign is still studied by military planners today.