The Valley of the Antietam--Gathering of the hosts--The battle-field--The battle commenced--Splendid fighting of Hooker's forces--Successes and reverses of Sumner's troops--Timely arrival of the Sixth corps--A gallant charge--Losses of the corps--Burnside's attack--Hours of suspense--The enemy defeated at all points--Retreat of the rebels--Scenes on the battle-field--At the hospitals--At Sharpsburgh--A division of militia--Couch's division joins the Sixth corps--Visit of the President--Recruits--Energy at the north--At rest--Want of clothing--Stuart's raid--Delays--Clear Spring--General Brooks. Chapter XV. The Second Advance into Virginia, and the Battle of Fredericksburgh. Marching in Maryland--Arrival at New Baltimore--General McClellan superseded by General Burnside--Thanksgiving in camp--The grand divisions organized--The march resumed--Fatal delays--In order of battle--The crossing--Fredericksburgh bombarded--Situation of Fredericksburgh--Scenes of activity--The Bernard house--Scenes at the hospital--The battle on the right--Charges of the Pennsylvania reserves--The river recrossed--Reflections. Chapter XVI. The Winter at Falmouth. Camp at White Oak Church--"The mud march"--Return to camp--General Neill--General Hooker supersedes General Burnside--Burnside's magnanimity--General Hooker as a soldier--Reconstruction--The cavalry organized--Business departments renovated--The medical department-- Ambulance system--Quartermasters' and commissary departments--Life in camp--Snowball battles--In the Seventy-seventh--The Light division--Review by General Hooker--General John Sedgwick--Scene at head-quarters--Review of the army by the President--Preparing for the campaign. Chapter XVII. The Chancellorsville Campaign. Orders to move--The river crossed--Sedgwick's command--The First corps withdrawn--Gallant conduct of the Light division--Advancing to the heights--The line of battle--The columns of attack--Attack of Howe's columns--Of Newton's column--Of Burnham's--Misfortune following victory--Fight of Bartlett's brigade--The First division at work--A critical position--The Sixth corps surrounded--Savage fight of Neill's brigade--The corps withdraws to Banks' Ford--Recrosses the river--Hooker's operations on the right--Position of the corps--Rout of the Eleventh corps--The rebels repulsed--Jackson renews the attack--The rebels again repulsed--Hooker recrosses the river. Chapter XVIII. Second Encampment at White Oak Church and the Pennsylvania Campaign. The army in its old position--A trip to Dixie--The wounded at the hospitals--Introduction of army badges--Adornments of the camps--The "Third crossing"--The Barnard mansion--Exchanging papers--A broken lieutenant--The Pennsylvania campaign commenced--Restriction of baggage--A severe march--An army bathing--At Centreville--Bristow Station--March to Maryland--General Hooker succeeded by General Meade--Position of the army. Chapter XIX. The Gettysburgh Campaign.