Which tactical mistake by santa anna gave the texans a major geographic advantage just before sam houston had his men begin their attack? a. he decided to take no prisoners of war b. he split his large army into five columns. c. he tried to capture the texas government at harrisburg d. he moved his men so that a ridge blocked their line of sight what gave a sense of urgency to the constitutional convention of 1836? a. the presence of santa anna's army b. u. s. interest in the annexation of texas c. disagreements over slavery in texas d, unfair british taxes and tariffs on imports

After Santa Anna's victory in San Antonio, at the Alamo, he felt overconfident and split his army into five columns after one of his generals, José Urrea, defeated a Texan army in Goliad. Near San Jacinto, Santa Anna ordered his reduced column to rest, and his biggest mistake was not to order patrols or sentries posted while the whole army was resting and Sam Houston was planning a surprise attack that his troops would execute with little difficulty as no alarm of attack was sounded and the whole Mexican army got completely caught by surprise.

As of the Constitutional Convention of Texas of 1836, whose delegates were elected in February 1, 1836, its sense of urgency was brought about by the approach of the Mexican Army led by Santa Anna which would arrive in Texas  a month later.