In 1942 Robinson joined the united states army, one of very few black officers. This was a difficult period for him. He soon found out that racial discrimination existed in the army too. At that time in Texas (and many other states), black people were supposed to sir at black of city buses, separate from white people. On army buses this was not the mile But one day, a bus driver on an army bus told Robinson to move to the back. He refused to do so. When the bus arrived at the army camp, he was arrested. Eventually, the army recognized that the bus driver was wrong and that Robinson should not have been arrested. By that time. The war was almost over.