One of the most notable of Lincoln's law cases was that in which he defended William D. Armstrong, charged with murder. The case was one which was watched during its progress with intense interest, and it had a most dramatic ending.
The defendant was the son of Jack and Hannah Armstrong. The father was dead, but Hannah, who had been very motherly and helpful to Lincoln during his life at New Salem, was still living, and asked Lincoln to defend him. Young Armstrong had been a wild lad, and was often in bad company.
The principal witness had sworn that he saw young Armstrong strike the fatal blow, the moon being very bright at the time.
Lincoln brought forward the almanac, which showed that at the time the murder was committed there was no moon at all. In his argument, Lincoln's speech was so feelingly made that at its close all the men in the jury-box were in tears. It was just half an hour when the jury returned a verdict of acquittal.
Lincoln would accept no fee except the thanks of the anxious mother.