The narrative in these pages follows chiefly the official reports, and it is believed will not be found to conflict seriously with them. Official reports, however, are liable to errors of statement and especially to the omission of facts, well known to the writer but not always to the reader, the want of which is seriously felt when the attempt is made not only to tell the gross results but to detail the steps that led to them. Such omissions, which are specially frequent in the earlier reports of the Civil War, the author has tried to supply by questions put, principally by letter, to surviving witnesses. A few have neglected to answer, and on those points he has been obliged, with some embarrassment, to depend on his own judgment upon the circumstances of the case; but by far the greater part of the officers addressed, both Union and Confederate, have replied very freely. The number of his correspondents has been too numerous to admit of his thanking them by name, but he begs here to renew to them all the acknowledgments which have already been made to each in person.