After graduating high school in 1947, James Hannah enlisted in the Army the next year and served on active duty with the 10th Engineer Battalion as a truck driver.  After his discharge in November 1949, he afforded a year out of the service before being recalled to active duty in September 1950 for the war in Korea.  During this period, his civilian occupation was automobile racing.

By December 1950, James was in Japan at the Eta Jima School for schooling in the radio operator's course.  Students came to Eta Jima School Command from Okinawa, Guam, and all other units stationed in Japan and the Far East for courses in Automotive Maintenance, Cooks and Bakers, Electrical Lineman, Signal Corps, Motion Picture Projection, Corps of Engineers, and more.  The course was six weeks and by February 1951, Cpl. Hannah was on his way to combat with the 1st Cavalry Division in Korea.

By this time, the 1st Cav had been up and down the peninsula and were currently holding positions around the village of Mugam-ni.  James joined HQ Company, 2d Battalion, 7th Cavalry Regiment as they were holding out on Hill 578, just south of the Han River and about 22 miles southeast of Seoul.  Snow from the previous winter was beginning to melt and the rainy season opened with torrential rains.  The 7th Cavalry moved northeast to assault the Hwachon reservoir area.  The dam was heavily defended by Chinese and it became the objective of 2d Battalion to attack from the southwest while other units approached from the east. The terrain was unsiutable for vehicles and was out of range of artillery fire, leaving the assault up to the troopers on foot.  The 1st Cav made three assaults on the dam, but were unsuccesful in pushing the Chinese out.  On April 17, a contingent of ROK troops moved in on the dam and found the positions evicted by the enemy.

Five days later, 21 Chinese and nine North Korean divisions rolled into Line "Kansas" in an effort to move into and capture Seoul.  The majority of the 1st Cavalry was in reserve at the beginning of the Communist attack, but soon joined the defense of the MLR after a collapse in the IX Corps sector left an opening for the enemy.  By April 28, the division occupied Line Golden north of Soul astride the main highways from Uijong-bu and Munsan-ni. The 1st Cav, under command of I Corps, was in a comfortable and fortified position on a narrow front that afforded a great field of artillery fire.  The Communists still pushed I Corps units back closer to Seoul in the rain and fog lasting through the month of May.  After days of fighting back, the 1st Cav had advanced north to Chorwon and crossed the 38th parallel for the third time since the division's arrival in Korea.  This era ended the offensive fighting in Korea and the war in the outposts began in the summer of 1951.

Routine patrols came and went from established outposts on prominent territorial features.  Hannah saw ten days of rest at the end of July when the 1st Cav went into reserve status, but by the first day of August, all regiments were on Line Wyoming, quickly resuming patrolling.  In mid August, the 5th and 7th Cavalry regiments sustained determined enemy attacks on their bases, receiving hundreds of rounds of artillery and mortar fire each day and often multiple attacks from the enemy.  On August 24, all five divisions under I Corps command suffered attacks throughout the day.  The 7th Cav was positioned near Sinchon at the time.

Early in the afternoon that day, Hannah was evacuated for a non-lethal but extremely unfortunate gunshot wound to the Corporal's privates.  Official records state this wound was an accidental injury caused by a friend who did not know his weapon was loaded.  "As to whether I was shot by a companion or not I honestly cannot say.  At the time I received the wound I passed out - I knew I had been shot but from whom or where I didn't know - later after I had received treatment and been in hospital for approximately 30 days - I returned to my original outfit.  I was told two different story's - One was I had been shot by a companion - the other was I had been shot by a sniper.  If I had been shot by a companion he shorly would have known the weapon was loaded.  In that area and practically every area that I was in all weapons were loaded and kept ready at all times" (1).  The medics picked up James and took him by jeep to the battalion aid station about 5 miles behind the lines.  After first aid, he went to the 8055th MASH in the Seoul area where surgeons stitched him back up.  Hannah spent the next month recovering at the Pusan General Hospital.

After a thirty day period of recovery, James returned to the 1st Cav Div on the line defending an eight mile front between Kyeho-dong and Kamgol - about 35 miles northeast from where he was wounded in August.  The first few days in October opened with heavy fighting on the front.  Every division in the area was enganged with the enemy, who was well defended and dug in.  Artillery rained down on enemy positions to soften them up for hours.  The 7th Cav, attacking with the Greeks, stormed Hills 313 and 418 along the ridge. Both the Greek and 2d Battalion fought their way to the ridge line, but niether held ground after taking heavy casualties.  The Chinese withdrew during the night, however, and the next day 2d Battalion stormed Hills 418 and 313 without opposition and by October 7 had moved into Hill 287.

Enemy losses during the period October 3-19 are estimated to total over 21,000, including 300 prisoners. Nearly 16,000 casualties had been inflicted upon the enemy by the 1st Cavalry Division alone.  On October 23 the new objective was to strengthen Line Jamestown by building defenses to prevent future enemy counterattacks. By the end of the month, Line Jamestown was seemingly secure in friendly hands.  Around this time, Hannah rotated home to Cedar Rapids, Iowa and was honorably discharged on November 17, 1951.  He married and had three children in light of his 'losses' in Korea.