That probably is a true statement. Some people argue that the conflict in Korea was not an officially declared war. In any event, yes, the US military fought there.
The US fought on the Allied, or UN side in Korea.
The Korean war ended in 1953, and US military involvement in Vietnam did not begin until 1965, although American Military Advisors and Covert Operatives had been active in Vietnam since 1954.
Korean War, aka Korean Conflict. The US was one of many participants.
Multiple wars were fought in the 20th century. A Few are World War One, World War Two, Korean War, Vietnam War, and the Gulf War. All these wars involved the US Military.
No- Obama's father was a Kenyan national - he was never in the US military and he never fought for the US. On the other hand, Barack Obama's maternal grandfather (Stanley Dunham) fought in World War II.
The Korean War (Korean Conflict)
The Korean War was the FIRST war in US History in which they were "Officially Integrated" into the US Military forces.
UN-United Nations
M48 Patton tanks entered US service after the Korean War and fought in the Vietnam War. The first of Patton series tanks, the M46 Patton, served in the Korean War. The M46 was simply a modified M26 Pershing tank. The M47 Patton never saw combat with the US military.
The Korean War was the first war fought by the USAF.
The US responded with military force.