During the Camden Expedition, Gen. Frederick Steele’s Union army left Little Rock on March 23, 1864, for a planned invasion of Texas and did not meet organized Confederate attacks until April 2. That day, Gen. Joseph Shelby attacked the Union wagon train at Terre Noire Creek, then struck Steele’s troops at Okolona on April 3, where fighting lasted for several hours in a furious thunderstorm before Shelby broke away and fell back to Antoine; a postwar account by Shelby’s adjutant claimed that a Union shell hit a hive and that bees, rather than gunfire, drove the Confederates from the field. Also on April 2, Union forces reached Elkins’ Ferry on the Little Missouri River and sent cavalry across to establish a picket line. Gen. John Marmaduke’s Confederate cavalry skirmished with them on April 3, prompting the Federals to send infantry and artillery reinforcements across the river. Marmaduke attacked in force with 1,600 horsemen on April 4 and pushed the Federals back toward the river, but troops from Iowa and Wisconsin crossed to strengthen the Union line, and Marmaduke fell back toward defensive earthworks on Prairie D’Ane.