Fighting between South Vietnamese and Communists continued despite the peace agreement until North Vietnam launched an offensive in early 1975. South Vietnam's requests for aid were denied by the U.S. Congress, and after Thieu abandoned the northern half of the country to the advancing Communists, a panic ensued. South Vietnamese resistance collapsed, and North Vietnamese troops marched into Saigon Apr. 30, 1975. Vietnam was formally reunified in July, 1976, and Saigon was renamed Ho Chi Minh City. U.S. casualties in Vietnam during the era of direct U.S. involvement (1961–72) were more than 50,000 dead; South Vietnamese dead were estimated at more than 400,000, and Viet Cong and North Vietnamese at over 900,000.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.