The armies of the North and South clashed 150 years ago at Bull Run. Both sides thought they would easily win, and both learned nothing is easy in war. (Frank Leslie)

In July 1861, time was running out for the 90-day volunteers — men who answered President Lincoln’s call for troops to put down the South’s rebellion. They had seen the unfinished dome of the Capitol, the stub of the Washington Monument, the President’s House and the Smithsonian Castle. But most hadn’t seen a rebel. Would they go home without fighting?

People in the North wondered that, too, and newspapers called for action. The words “On to Richmond!” seemed to be everywhere, urging an attack on the Confederate capital. Both the president and their general knew the 90-day men weren’t well-trained soldiers yet, but Lincoln figured that the Confederate volunteers weren’t ready for battle either. So Gen. Irvin McDowell made plans to attack Confederate Gen. P.G.T. Beauregard’s army, 30 miles from Washington.

When the Union soldiers began to stream across the bridges into Virginia, people knew the battle would begin soon. And they were sure the fighting would be near Bull Run — a creek the Union Army would have to cross to reach Manassas Junction, where the Confederates were camped.

Two Virginia railroads met in a “Y” at Manassas Junction. One led to Richmond, the other to the Shenandoah Valley. The Confederates were determined to defend these important routes. They planned to make their stand along Bull Run and drive the Union Army back. They were sure they would win the battle — and the South’s independence.

Lincoln’s 90-day men were just as sure they would win the battle. They would beat those rebels, then continue on to Richmond. That would end the war and save the Union.

But the battle, fought 150 years ago this week, wasn’t the easy victory either side expected. Or the great adventure many young volunteers looked forward to. Instead, it was the worst experience of their lives. Clouds of smoke from weapons firing made it hard for them to see or breathe. The noise terrified them as cannons thundered, firearms blasted, drums beat, bugles blew, men shouted and cried out in pain. The officers had their problems, too. Maps were wrong. Orders were lost. Carefully made battle plans didn’t work.

All day long, men fought and died. By noon, the Union was winning, but then Confederate reinforcements began to arrive and pushed the Union soldiers back. For many, the retreat turned into an every-man-for-himself rush toward Washington. Union soldiers coming from two directions met at a creek crossing and found the bridge blocked by an overturned army wagon. To make things worse, the Confederate cannon fire that caused the wagon to overturn was now aimed at them! Panicked, men threw down their weapons, abandoned their equipment, and plunged into the creek. Many were captured.

In Washington, people were sure the Confederates would capture the city. But they were too exhausted and too disorganized to even try.

Nearly 5,000 men had been killed, wounded or captured at Bull Run. The North was stunned by the defeat. The South was shocked by how many men their victory had cost. People on both sides had thought one great battle would end the war. But now they realized they were in for a long, hard, bloody struggle.

— Carolyn Reeder

Reeder is giving readers a kid’s-eye view of the Civil War. Her books include “Shades of Gray” and “Captain Kate.”