Fifty-three years after the Siege of Petersburg ended, soldiers again gathered on the fields in front of Petersburg, this time from a united country preparing to enter World War I. Shortly after war was declared on April 6, 1917, the War Department established Camp Lee, where soldiers spent long days training in muddy trenches built on the same ground contested in 1864-65. The surviving trenches there helped prepare American Doughboys for fighting in France, and one field of about 20 acres across a ravine from the parade ground served the Field Fortification School, where classes dug trenches of various types with revetted sides of different design. British Army Sergeant Jack Roseborm also helped soldiers of the 80th Division construct trenches there.