Lincoln's proclamation of the first Thanksgiving Day in November 1963, is the occasion for a story of Lincoln's secretary's involvement with a Confederate spy who is his brother-in-law.Lincoln's proclamation of the first Thanksgiving Day in November 1963, is the occasion for a story of Lincoln's secretary's involvement with a Confederate spy who is his brother-in-law.Lincoln's proclamation of the first Thanksgiving Day in November 1963, is the occasion for a story of Lincoln's secretary's involvement with a Confederate spy who is his brother-in-law.