NEW YORK –  The first Civil War casualty to be buried in Green-Wood Cemetery in Brooklyn was a 12-year-old drummer for a New York regiment.

Clarence McKenzie, a local boy fatally wounded in an accidental shooting in Maryland, was buried June 14, 1861, two months after the Union garrison at Fort Sumter surrendered to Confederate forces. He was followed to the grave 12 days later by Adolph Vincens, a 23-year-old London-born jeweler who was the first Civil War battle casualty buried at Green-Wood.

By the time the war ended four years later, about 200 other soldiers and sailors who died in the Civil War were buried at Green-Wood, established in 1838 in what was then a rural section of Brooklyn. In the decades after the war, thousands of others would join their comrades — and even some of their one-time enemies — at the historic cemetery.

Today, the 478-acre expanse of greenery and statuary covering the cemetery's rolling hills is believed to be the final resting place of about 8,000 Civil War veterans.

A team of volunteers and Green-Wood staff has spent nearly a decade trying to identify all those graves. When the project began in September 2002, cemetery officials figured they had, at most, 500 veterans of the nation's bloodiest war buried here....