The A Sầu Valley was a vital corridor for moving military supplies coming from the Ho Chi Minh Trail and was used by the People's Army of Vietnam (PAVN) as a staging area for numerous attacks in northern I Corps.

[1][2]: 182–92 In January 1968, Military Assistance Command, Vietnam (MACV), ordered the 1st Cavalry Division (Airmobile) to move north from the Central Highlands to support the III Marine Amphibious Force in I Corps.

Because of this strength on the ground, and the relative geographic isolation of the valley, the U.S. and its allies conducted little offensive activity in the area except for air attacks, and those were limited by steep, mountainous terrain often cloaked under clouds and prone to sudden, violent changes in weather.

Besides maintaining a margin of security for his troops, the embargo would cover the insertion of a reconnaissance force of up to battalion size into Laos at a point above where the valley entered South Vietnam.

Following reports by syndicated columnist Joseph Alsop filing in Hong Kong and South Vietnamese information officers announcing that their units were involved in the operation, MACV lifted the press embargo after 8 days.

[8]: 91 On 21 April the Cavalry units continued to push further down the valley, while the 2nd Battalion, 502nd Infantry Regiment was landed near Firebase Veghel to support the 1/327th and 6th ARVN Airborne.

Sprayberry personally killed 12 PAVN soldiers and eliminated 2 machine gun emplacements, he was subsequently promoted to captain and awarded the Medal of Honor for his actions.

The PAVN had the upper hand because they fought from well-made bunkers and camouflaged positions in the trees and at one point sent out a force to envelop Company B.

[8]: 91  As the 1st Cavalry Division kept sweeping south through the valley it linked with the other allied units that served as blocking forces and uncovered large caches of weapons, vehicles, ammunition, and rice.

[12]: 539  Bad weather aggravated the loss by causing delays in troop movements, allowing a substantial number of PAVN to escape to safety in Laos.

[1] Nevertheless, Operation Delaware was hailed as a success by the United States, but the withdrawal of US and ARVN troops made it possible for PAVN forces to quickly regain control of the valley.

[14] This article incorporates public domain material from websites or documents of the United States Army Center of Military History.