51 December NVA units encircle Phuoc Long City (Song Be), capital of Phuoc Long Province, near the Cambodian border in Military Region 5.

1975--7 January The NVA captures Phuoc Long Province. 27 January The last allied Mekong River convoy from South Vietnam enters

Phnom Penh. The Cambodian Communist Khmer Rouge have successfully halted resupply to the embattled Cambodian capital, threatening the downfall of the non-Communist Cambodian Government.

10 March The NVA attacks Ban Me Thuot in the Central Highlands, marking the start of its 1975 Spring Offensive.

19 March The South Vietnamese abandon Quang Tri City and Province.

24 March Quang Ngai City and Tarn Ky in I Corps fall to the advancing NVA.

25 March Hue falls to the Communists.

26 March The NVA captures the former U.S. Marine base of Chu Lai.

30 March The NVA enters the major port city of Da Nang and captures the

Da Nang Air Base.

12 April Marines of the 9th Marine Amphibious Brigade (9th MAB) execute Operation Eagle Pull, the evacuation of American and other foreign nationals from Phnom Penh, just before the city falls to the Khmer Rouge.

21 April Nguyen Van Thieu resigns as President of the Republic of Vietnam (South Vietnam) and departs Saigon four days later for Taiwan, leaving the control of the government in the hands of his vice president.

28 April General Duong Van Minh becomes the new President of the Republic of Vietnam,

29 April Marines of the 9th MAB execute Operation Frequent Wind, the

evacuation of Americans, foreign nationals, and various Vietnamese

officials and citizens associated with Americans from Saigon to

ships of the Seventh Fteet.

50 April The North Vietnamese Army enters Saigon and places General

Minh and his cabinet under arrest. Organized South Vietnamese

resistance to the NVA has collapsed.

12 May A gunboat of the new Cambodian Khmer Rouge regime seizes an

American ship, the SS Mayaguez, in the Gulf of Thailand.

14 May Marines of BLT 2/9 in U.S. Air Force helicopters make a helicopter assault on Koh Tang Island off the Cambodian mainland where the crew of the Mayaguez is believed to be held. At the same time, Marines from Company D, 1st Battalion, 4th Marines board the Mayaguez only to find it deserted. The Cambodians in the meantime release the crew of the Mayaguez who later are recovered at sea by the U.S. destroyer Wilson.

15 May With the recovery of both the Mayaguez and its crew, the Marines withdraw from Koh Tang Island. The American forces sustained total casualties of 15 killed, 3 missing in action (later declared dead), 49 wounded, and 23 other personnel killed in a related helicopter crash. U.S. forces inflicted an unknown number of casualties.