Cagney's Cohan is walking down a marble staircase at the White House when he suddenly starts tapping and improvises all the way to the bottom. He gets a telegram summoning him to the White House, and arrives on foot, drenched, late at night. That sets off an entire film of flashbacks, narrated by Cohan, as he tells the president his life story. No wonder that when the aging George M. Cohan himself was shown the movie, he liked it. Cohan sees himself as a flag-waver, and the critics attack him for writing only lightweight musical comedies.
Every scene follows the themes.
He does a tap dance in the recruiting office to demonstrate what he means, walks outside and catches two notes from a marching band. Finally comes the White House visit and, after Cohan has told the patient FDR his entire life story, a private presentation of the Medal of Honor. The cinematography, by the legendary James Wong Howe, uses the elegant compositions of figures that were common at the time, and the staging includes two numbers where big studio treadmills are used to move groups of extras, or keep them marching in place. But the greatness of the film resides entirely in the Cagney performance. Even Walter Huston, one of the finest character actors of the era, is confined by routine material.