Advance elements of the 24th Infantry Division were badly defeated in the Battle of Osan on July 5, during the first battle between US and KPA forces.
The force at the battle, Task Force Smith, retreated from Osan, and US forces were again defeated in the Battle of Pyongtaek.
For over a week after the defeat of Task Force Smith, 24th Infantry Division soldiers were repeatedly defeated and forced south by the KPA's superior numbers and equipment.
The 24th Infantry Division was systematically pushed south at and around Chochiwon, Chonan, Pyongtaek, Hadong, and Yechon.
These American soldiers, most of whom had experienced only occupation duty in Japan and no actual combat, were unprepared compared to the more disciplined North Korean units.

On July 12, the division's commander, Major General William F. Dean, ordered the division's 19th, 21st and 34th Infantry Regiments to cross the Kum River, destroying all bridges behind them, and to establish defensive positions around Taejon.
Taejon was a major South Korean city 100 miles (160 km) south of Seoul and 130 miles (210 km) northwest of Pusan, and was the site of the 24th Infantry Division's headquarters.
Dean formed a line with the 34th Infantry and 19th Infantry facing east, and held the heavily battered 21st Infantry in reserve to the southeast.
The Kum River wrapped north and west around the city, providing a defensive line 10–15 miles (16–24 km) from the outskirts of Taejon, which is protected on the south by the Sobaek Mountains.
With major railroad lines and roads emanating in all directions, Taejon stood as a major transportation hub between Seoul and Taegu, giving it great strategic value for both the US and KPA forces.
Taejon had to be held to stop the North Korean forces from converging on the unfinished defensive lines around Pusan.
Advance elements of the 24th Infantry Division were badly defeated in the Battle of Osan on July 5, during the first battle between US and KPA forces. The force at the battle, Task Force Smith, retreated from Osan, and US forces were again defeated in the Battle of Pyongtaek. For over a week after the defeat of Task Force Smith, 24th Infantry Division soldiers were repeatedly defeated and forced south by the KPA's superior numbers and equipment. The 24th Infantry Division was systematically pushed south at and around Chochiwon, Chonan, Pyongtaek, Hadong, and Yechon. These American soldiers, most of whom had experienced only occupation duty in Japan and no actual combat, were unprepared compared to the more disciplined North Korean units.
On July 12, the division's commander, Major General William F. Dean, ordered the division's 19th, 21st and 34th Infantry Regiments to cross the Kum River, destroying all bridges behind them, and to establish defensive positions around Taejon. Taejon was a major South Korean city 100 miles (160 km) south of Seoul and 130 miles (210 km) northwest of Pusan, and was the site of the 24th Infantry Division's headquarters. Dean formed a line with the 34th Infantry and 19th Infantry facing east, and held the heavily battered 21st Infantry in reserve to the southeast. The Kum River wrapped north and west around the city, providing a defensive line 10–15 miles (16–24 km) from the outskirts of Taejon, which is protected on the south by the Sobaek Mountains. With major railroad lines and roads emanating in all directions, Taejon stood as a major transportation hub between Seoul and Taegu, giving it great strategic value for both the US and KPA forces. Taejon had to be held to stop the North Korean forces from converging on the unfinished defensive lines around Pusan.
Chaplain–Medic massacre