Allan Smith Holbrook was born in East Boston, Massachusetts on August 1, 1874. He later moved to Lyndonville, Vermont where he published the Lyndonville Journal. After selling the newspaper, he moved to Dwight, Illinois and became a partner, Editor, and Publisher of the Dwight Star and Herald.

His father, Samuel Harrison Holbrook was a 2nd Lieutenant with the 1st Regiment, Vermont Heavy Artillery and served from August 11, 1862 to June 24, 1865. He had enlisted as a private.

Allan followed in his father's footsteps, serving with Company L, 1st Vermont Infantry during the Spanish American War.

Allan joined the Henry Fox Camp 270 and was a Department Commander for Illinois (1923). He was the long time published and printer of The Banner. The 1930 election for Commander-in-Chief was Holbrook against William Schneider, PDC of Missouri. Holbrook received 125 votes and Schneider received 13 votes. Brother Schneider asked that the election become unanimous for Brother Holbrook and the National Encampment agreed.

Brother Holbrook was active in civil and fraternal organizations. Allan was the President of the Dwight Memorial Day Association, lead the dedication of the GAR Highway in Illinois in 1947, active in the Dwight Congregational Church, a member of the Livingston Lodge No. 371, A.F. and A.M., Bloomington Consistory, and Mohammed Shrine in Peoria. He also served on the Dwight School Board.

He married Charlottle Stiles and they had three sons: Paul, Roger, and Dudley. He would later marry Minnie Orr.

Allan died on May 14, 1956 at the Dwight Veterans Hospital. At his funeral service he received a military escort with members of the American Legion and Veterans of Foreign Wars in attendance. He is buried at the Lake Road Cemetery in Newport, Vermont.