Thousands of reenactors, on foot and on horseback, thundered across sweltering fields north of Manassas Saturday to re-fight the Battle of Bull Run and mark the 150th anniversary of the first major clash of the Civil War.

An estimated 8,700 reenactors from the U.S., Canada and Great Britain restaged the battle, starting at 9:30 a.m., on a 177-acre site off Pageland lane, near Route 29, in Gainsville.

Perspiring Yankees and Confederates, clad in colorful period uniforms, fired rifle volleys and cannon shots _ minus bullet and shell _ as they had a century and a half ago, amid shouts, and cavalry charges and numerous “casualities.”

Despite the broiling heat, the event was watched by several thousand spectators, assembled on bleachers and along the sidelines of the battlefield.

The reenactment is scheduled to be repeated Sunday. Ticket information can be found at

Local officials have been concerned about the extremely hot weather, which has dogged the commemorations since Thursday’s actual anniversary date. The temperature could reach 100 Saturday. Sunday could be slightly cooler, with readings in the 90s and thunder storms, the National Weather Service said.

The real battle, between Union and Confederate forces, was fought July 21, 1861, as a raw volunteer northern army attempted to dislodge and equally raw southern army from the crucial rail hub of Manassas Junction.

It was a humiliating defeat for the Union, and a triumph for the Confederacy.

Scores of reenactors have assembled at an adjacent camp site in recent days, bringing colorful, but hot, 1860s uniforms, as well as equipment.

Many arrived towing Civil War artillery pieces, and some of the more than 400 hundred horses being ridden by the “cavalry.”

The guns and cannon are using gunpowder, but no projectiles.

About 1,000 men on both sides, combined, died in the battle, which in the South often is called the Battle of Manassas.

The Civil War, which began in 1861 and ended in 1865, claimed more than 600,000 lives — 2 percent of the population then. Today, a roughly equivalent loss would mean 6 million dead, historians have said.

Since April, the nation has been marking the Sesquicentennial of the war.

The reenactment site will be open Sunday to spectators from 6:30 a.m. to 2 p.m. Living History demonstrations, and the food and merchandise vendors will also be open for business from 6:30 a.m. until 2 p.m.

Officials caution that there is no onsite parking, or walk-up admission.

All vehicles should park at Jiffy Lube Live, 7800 Cellar Door Drive, Bristow. Free shuttle buses will provide transportation to and from the event site from 6 a.m. until 3 p.m. The shuttle bus ride last about 15 minutes.