He was born November 11, 1811, in Rutherford County, Tennessee, one of twelve children and the fourth son of Alexander McCulloch and Frances Fisher LeNoir.

Benjamin's father Alexander, a Yale University graduate, was a descendant of Captain Nicolas Martiau, the French Huguenot settler of Jamestown, Virginia and ancestor of President George Washington, and also had Scots-Irish ancestry.

The McCulloch family had been wealthy, politically influential, and socially prominent in North Carolina before the American Revolution, but Alexander had wasted much of his inheritance and was unable even to educate his sons.

Assigned to Captain Isaac N. Moreland's artillery company at the Battle of San Jacinto (April 21, 1836), he commanded one of the "Twin Sisters"—two six-pounder cannon sent to aid the Texans by the citizens of Cincinnati.

The campaign was contentious, and McCulloch fought a rifle duel the next year against Colonel Reuben Ross, resulting in a wound that left his right arm crippled for life.

Ben considered the matter closed, but it flared up again the following year, this time involving Henry McCulloch, who killed Ross with a pistol.

He and his brother, Henry, subsequently took part in the failed Somervell expedition and both escaped very shortly before most of the Texans were captured at Ciudad Mier, Mexico in Tamaulipas, December 25, 1842.

Samuel Reid, a volunteer from Louisiana, described McCulloch and his ranger company as "men in groups with long beards and mustaches, dressed in every variety of garment, with one exception, the slouched hat, the unmistakable uniform of a Texas ranger, and a brace of pistols around their waists, [who] were occupied drying their blankets, cleaning and fixing their guns, and some employed cooking at different fires, while others were grooming their horses.

By this time, McCulloch was fluent in Spanish and his woodsman's skills enabled him to slip back and forth across the lines undetected—more than once penetrating to within a mile of Santa Anna's own tent.

In 1852, President Franklin Pierce promised him command of the U.S. Second Cavalry, but Secretary of War Jefferson Davis gave it instead to Albert Sidney Johnston.

The Buchanan pardon was non-negotiable: 1) submit to Federal authority, and 2) allow the army to pass through Salt Lake City and establish a post somewhere in Utah.

Brigham accepted the pardon under protest that the members of the Church had committed no crimes other than burning the US Army supply train contracted with Majors & Waddell, on the high plains of Wyoming.

Subsequently, on the morning of February 16, U.S. Army General Twiggs, finding that more than 1,000 Texas troops had surrounded his installations in an orderly manner during the night, turned over to McCulloch all federal property in San Antonio.

He disagreed strongly with General Sterling Price of Missouri, but with the assistance of Brigadier-General Albert Pike, he was able to build alliances for the Confederacy with the Cherokee, Choctaw, and Creek nations.

On August 10, 1861, McCulloch's troops, though relatively poorly armed, handily defeated the army of Brigadier-General Nathaniel Lyon at the Battle of Wilson's Creek, Missouri.

He did not have a high opinion of Price's Missourians, noting that they were undisciplined, commanded mostly by incompetent and inexperienced politicians, and possessed only a poor mix of weapons and equipment.

His lack of confidence in the Missourians led McCulloch to hesitate when a bold attack might well have destroyed Lyon's smaller force and given Missouri to the Confederacy.

McCulloch commanded the Confederate right wing at the Battle of Pea Ridge (or Elkhorn Tavern), Arkansas, and on March 7, 1862, after much maneuvering his troops overran a key Union artillery battery.

Union resistance stiffened late in the morning, however, and as McCulloch rode forward to scout out enemy positions, he was shot out of the saddle and died instantly.

McCulloch always disliked army uniforms and was wearing a black velvet civilian suit and Wellington boots at the time of his death.

Historians generally blame the Confederate disaster at Pea Ridge and the subsequent loss of undefended Arkansas on the death of McCulloch.

Shortly after Pea Ridge, Albert Pike, now a brigadier-general, constructed Fort McCulloch as the principal Confederate fortification in the southern section of the Indian Territory, naming it after his late commander.

It is now a public recreation facility of some 200 acres (0.8 km2), operated by the County of Hays, and is a popular location for Central Texas family reunions, picnics, and musical festivals.