 During this time , Vandegrift continued to direct efforts to strengthen and improve the defenses of the Lunga perimeter . Between 21 August and 3 September , he relocated three Marine battalions — including the 1st Raider Battalion , under U.S. Lieutenant Colonel Merritt A. Edson ( Edson 's Raiders ) , and the 1st Parachute Battalion — from Tulagi and Gavutu to Guadalcanal . These units added about 1 @,@ 500 troops to Vandegrift 's original 11 @,@ 000 men defending Henderson Field . The 1st Parachute battalion , which had suffered heavy casualties in the Battle of Tulagi and Gavutu @-@ Tanambogo in August , was placed under Edson 's command . 
