General Chamberlain's Courage

Ellis Spear, an officer in the 20th Maine, was close by but did not directly witness Chamberlain's charge on June 18, 1864. He would visit Chamberlain in the field hospital where he likely heard the story from others, and undoubtedly at some point he heard the story from Chamberlain. The one obvious error being that Chamberlain was taken to City Point and then to Annapolis not Fortress Monroe.
    Though there are many accounts like this one that show Chamberlain's horse Charlemagne being wounded in the same charge where Chamberlain was wounded, Chamberlain in his own account describes his horse going down earlier in the day.1 Also in The Hero of Gettysburg he states, "I felt it my duty to lead the charge in person, and on foot."

Other comments made by Ellis Spear on the dedication of Bowdoin's Memorial hall, according to the Boston Evening Transcript on page 3, "The allusion of General Spear to the fact that he remembered to have seen President Chamberlain, not as well dressed as today, but doing gallant service as he charged with his troops down the slopes of Gettysburg, was greeted with rapturous and well-merited applause."

This account was also copied into the history of the 9th Massachusetts Battery.
1Smith, Diane M. Chamberlain at Petersburg. pg 54.