Question: What doctor survived the massacre that took place March 27, 1836, during the Texas Revolution?

Context paragraphs:
John Parker (pioneer): Elder John Parker (September 6, 1758 – May 19, 1836) was an American patriot, veteran of the American War of Independence, scout and minor diplomat for the American government, famous frontier Ranger, noted Indian fighter, Texan settler, and Predestinarian Baptist minister.  He helped settle Texas before the Texas Revolution, and was immortalized in death when he was killed during the Fort Parker massacre in 1836, along with several members of his family, and others of the "Parker clan".

James Fannin: James Walker Fannin Jr. (1804/1805 – March 27, 1836) was a 19th-century U.S. military figure in the Texas Army and leader during the Texas Revolution of 1835–36.  After being outnumbered and surrendering to Mexican forces at the Battle of Coleto Creek, Colonel Fannin and nearly all his 344 men were executed soon afterward at Goliad, Texas, under Santa Anna's orders for all rebels to be executed.

Grass Fight: The Grass Fight was a small battle during the Texas Revolution, fought between the Mexican Army and the Texian Army.  The battle took place on November 26, 1835, just south of San Antonio de Béxar in the Mexican region of Texas.  The Texas Revolution had officially begun on October 2 and by the end of the month the Texian had initiated a siege of Béxar, home of the largest Mexican garrison in the province.  Bored with the inactivity, many of the Texian soldiers returned home; a smaller number of adventurers from the United States arrived to replace them.  After the Texian Army rejected commander-in-chief Stephen F. Austin's call to launch an assault on Béxar on November 22, Austin resigned from the army.  The men elected Edward Burleson their new commander-in-chief.

Jack Shackelford: Jack Shackelford (March 20, 1790 – January 22, 1857) was an American doctor, politician and soldier.  He raised and led a unit called the Red Rovers or the Alabama Red Rovers to fight in the Texas Revolution.  He was one of the few survivors of the Goliad massacre.

Ira Westover: Ira J. Westover (1795 – March 27, 1836) was an officer in the Texian Army who served in the Texas Revolution, leading a force during the Battle of Lipantitlán.  He and his adopted son were killed in the Goliad Massacre.

Runaway Scrape: The Runaway Scrape events took place mainly between September 1835 and April 1836, and were the evacuations by Texas residents fleeing the Mexican Army of Operations during the Texas Revolution, from the Battle of the Alamo through the decisive Battle of San Jacinto.  The "ad interim" government of the new Republic of Texas and much of the civilian population fled eastward ahead of the Mexican forces.  The conflict arose after Antonio López de Santa Anna abrogated the 1824 constitution of Mexico and established martial law in Coahuila y Tejas.  The Texians resisted and declared their independence.  It was Sam Houston's responsibility, as the appointed commander-in-chief of the Provisional Army of Texas (before such an army actually existed), to recruit and train a military force to defend the population against troops led by Santa Anna.

Convention of 1836: The Convention of 1836 was the meeting of elected delegates in Washington-on-the-Brazos, Texas in March 1836.  The Texas Revolution had begun five months previously, and the interim government, known as the Consultation, had wavered over whether to declare independence from Mexico or pledge to uphold the repudiated Mexican Constitution of 1824.  Unlike those of previous Texas councils, delegates to the Convention of 1836 were younger, more recent arrivals to Texas, and more adamant on the question of independence.  As delegates prepared to convene, Mexican President Antonio Lopez de Santa Anna led a large army into Texas to quell the revolt; the vanguard of this army arrived at San Antonio de Bexar on February 23.

Battle of the Alamo: The Battle of the Alamo (February 23 – March 6, 1836) was a pivotal event in the Texas Revolution.  Following a 13-day siege, Mexican troops under President General Antonio López de Santa Anna launched an assault on the Alamo Mission near San Antonio de Béxar (modern-day San Antonio, Texas, United States), killing all of the Texian defenders.  Santa Anna's cruelty during the battle inspired many Texians—both Texas settlers and adventurers from the United States—to join the Texian Army.  Buoyed by a desire for revenge, the Texians defeated the Mexican Army at the Battle of San Jacinto, on April 21, 1836, ending the revolution.

Burr H. Duval: Burr Harrison Duval (1809 – March 27, 1836) was the commander of the Kentucky Mustangs, First Regiment Volunteers, a group of Kentucky long-riflemen formed in Bardstown, Kentucky, in November 1835 during the Texas Revolution.  He and hundreds of others surrendered to the Mexican army at Goliad, Texas, only to be executed in the Goliad Massacre.

Goliad massacre: The Goliad massacre was an event that occurred on March 27, 1836, during the Texas Revolution, in which nearly 500 prisoners of war from the army of the Republic of Texas were killed by the Mexican Army in the town of Goliad, Texas.  Among those killed was commander James Fannin.  The killing was carried out under orders from General and President of Mexico Antonio Lopez de Santa Anna.  Despite the protests for clemency by General José de Urrea, the massacre was reluctantly carried out by Lt. Colonel José Nicolás de la Portilla.

Supporting paragraphs: Jack Shackelford Goliad massacre
Answer: Jack Shackelford