[1] After attending the public schools at Milford and Lewes, he ran the Blackwater general store started by his grandfather.

Tunnell was a member of the Delaware House of Representatives in the 1871/72 session and Clerk of the Peace for Sussex County from 1885 through 1890.

Two years later, in 1896, he was elected governor, defeating the Union (Addicks) Republican Party candidate, James R. Hoffecker, and the regular Republican Party candidate John C. Higgins.

Among many other changes, it created the office of Lieutenant Governor, allowed governors to be elected to a second term and gave them a legislative veto, reduced judges' terms from life to 12 years, and eliminated the poll tax.

Members of the Delaware General Assembly took office the first Tuesday of January.