Ah yes, Joshua Chamberlain, the David Ireland of the Left.
Chamberlain was a fine soldier, but Killer Angels made his modern reputation. That's not to detract from his conduct on Little Round Top or subsequently, but David Ireland and the 137th New York did everything on Culp's Hill that Chamberlain and the 20th Maine did on Little Round Top: held the extreme right, battle in the balance, assailed by three times their number of rebs, extended the line, shifted position, refused the flank, held despite heavy casualties. But most people have never heard of them.
Chamberlain survived to write several books, toot his own horn with gusto, and enjoy a brilliant postwar career, all of which made him an easy figure for Michael Shaara to resurrect. Ireland was mortally wounded at Resaca the next summer. On such things does fame depend.
There were lots of heroes at Gettysburg.
Unfortunate phrasing on my part when I said "if." Didn't mean it that way.