The correct answer is FALSE.
The First Battle of Bull Run was the first major battle of the US Civil War, fought by the Union forces and the Confederate forces in 1861. The Union forces were very disorganized and slow to position themselves, therefore the Confederates could call for reinforcements, that arrived by train, and managed to win the battle.
Therefore, the defeat was not good for enhacing the motivation of the Union Army. They realized they needed tactical intelligence and better artillery and organization if they wanted to defeat the Confederates supress the rebellion.