Daniel B. Ainger was born in Bellevue, Ohio, March 9, 1844. When Ainger was only 17 years old he enlisted with the Union army to fight in the great conflict between North and South in 1861. He became a member of Company K, Second Ohio Cavalry, and spent eighteen months on the front. He then returned home due to a disability.

When he recovered, he re-enlisted with Company A, Twenty-third Infantry, under the Command of the future president, then Colonel Rutherford B. Hayes. He remained with this regiment until the end of the war.

Ainger started his journalist career at the Fremont Journal in Ohio at age 21. In 1877 he bought the Charlotte Republican. Ainger made the Republican one of the foremost journals in Southern Michigan, whose influence was felt in molding public opinion on all the issues of the day. The topics were broad and catholic in spirit and always soundly Republican.

Ainger served as the Chairman of the County Republican Committee, and was prominent in the councils of his party as member of the Executive Board of the Republican State Central Committee. During the administration of his old commander, President Hayes, he was Postmaster General at Washington, D.C. For four years he was Adjutant General of the State of Michigan with the rank of Brigadier General during the administration of Governor Luce.