Books: They Saw It Happen

GETTYSBURG (308 pp.)—Earl Schenck Miers and Richard A. Brown—Rutgers ($3.50).

Crossing a road near Gettysburg, 13-year-old Billy Bayly met a mud-splashed Union cavalryman. Said Billy: "Hello . . . What's up?" ". . . You'll find out what's up," snapped the soldier, "the Rebel cavalry [are] close on my heels ... git or you'll be got."

Billy didn't git; like any boy, he was thrilled at the prospect of seeing a real battle. When the Army of Northern Virginia hove in sight, "wave after wave, billow after billow," Billy was squatting on top of a fence, all set to see the fun.

Billy...