The words of the Gettysburg Address on the plaque was (probably) taken at the New Albany National Cemetery in Floyd Co., IN.
William McDougall (1822-1905), a Canadian politician, was present during the original Gettysburg Address given by President Abraham Lincoln on November 19, 1863.
William McDougall was the father-in-law of Jane Howard. Jane was also the first cousin of my 2nd great-grandmother, Mary Agnes Kennedy.
Update: The National Archives site has a rare photo of Lincoln at Gettysburg here.