The Grand Army of the Republic, or G.A.R. was a large veterans' organization founded in 1866 by a Union Army Surgeon, Benjamin Franklin Stephenson. Membership was limited to veterans of the Civil War. The organization, originally, was intended to be a brotherhood of veterans who joined together to help other veterans. It was, at times, a fraternal lodge, a charitable society, a special interest lobby group, a patriotic group and a political club.
The G.A.R. founded veterans' homes and was active in relief work and pension legislation. Five members of the G.A.R. were elected president of the United States [Ulysses S Grant, Rutherford B. Hayes, James A. Garfield, Benjamin Harrison, and William McKinley] and, at one time, it was impossible to be nominated for a Republican office without the backing of the G.A.R.
In the beginning, each post was set up similar to a Union Army encampment. This military system lasted only until 1869 when it was replaced by a fraternal order similar to the Masonic Lodges. This system did not appeal to the majority of veterans. There were strict rules and grading systems for members. By the early 1870s, membership had plummeted.
By the l880s, however, membership rose sharply. Changes in the organizational system and dropping the grading system resulted in a large increase in membership. In 1890, the G.A.R. reached its largest membership of over 490,000 veterans. There was even an Abraham Lincoln Post Number 634 in Lima, Peru. This post, established February 12, 1890, was made up of members of the United States Legation, construction engineers, developers and prospectors.