Short answers, pulled from the story.
The first shots of the battle were fired at around 5:00 am on the 10th of August 1861. Union forces under Brigadier General Nathaniel Lyon engaged Confederate and Missouri State Guard troops near Springfield.
Brigadier General Nathaniel Lyon led the Union army until his death on Bloody Hill shortly before 9:00 am. Command subsequently passed to Colonel James Sturgis and later Major Franz Sigel after the Union retreat.
Around 1,317 Union soldiers were killed, wounded, or captured while an estimated 1,222 Confederate, Missourian, or Arkansan soldiers suffered similar fates. Nearly a quarter of Lyon's force became casualties during the engagement.
The primary combat occurred on a ridge known as Bloody Hill southwest of Springfield in Missouri. Union artillery and infantry positions were established there while Southern forces attacked from surrounding areas.
Lyon died when he led a counterattack by the 2nd Kansas regiment shortly before 9:00 am after his horse was killed and he was wounded in the head and right leg. He became the war's first battle death for a Union general.