was born at York Co., Pennsylvania
, on 21 June 1763. He was the son of William McClellan Sr.
and Eleanor McMichael
. He married Maria Magdalena Spangler
on 31 January 1788. In 1792 he was a candidate for Sheriff of York Co., Pennsylvania and announced his candidacy in the Pennsylvania Herald and York General Advertiser with the following advertisment: "To the Freeman Electors of the County of York. Gentlemen: - Although two years have elapsed since I had the honor of soliciting your votes and interest for the Sheriff's Office, yet your former spirited and generous exertions in my behalf, have made an impression on my mind, that again demand my warmest acknowledgements, and embolden me once more to come forward, and solicit your suffrages at the ensuing election; a similar exertion will, I trust, procure the Sherriff's Office; Should I obtain it, no one will pay more attention to the duties of such an important trust, or discharge the same with more lenity and fidelity; relying on your generosity, I am, Gentlemen, Your most obedient, Most devoted Humble Servant. March 13, 1792 William McClellan. During the ensuing election in October, 1791, Godfrey Lenhart received 2,399 votes and William McClellan 2,345. He was subsequently elected Sheriff of York Co. during the next election and held that position from 1795 to 1798, in which year he was elected Captain of the York Volunteer Corps of Cavalry. From the Pennsylvania Herald and York Advertivers of 1798 come the following notices: "NOTICE Such gentlemen as already have joined the Corps of Cavarly, now raising in the Borough of York and vicinity - as well as those who wish to do so - are informed, that an election will positively be held on Saturday the 14th inst., at 2 o'clock p.m. in the Court House - for the purpose of electing officers. According to the rules adopted, no member can be permitted to vote, who does not appear dressed in uniform. York, July 11, 1798." "NOTICE Those who incline to enrol themselves in the York Corps of Cavarly, may apply to Captain William McClellan; those who prefer to join the Infanty Company now raising, to Captain John Edie - Captain Gossler's being filled. Applications may also be made to the individuals in each Corps. Agreeable to the public notice given, an election was held on Saturday last, at the Court House, in this Borough, for officers in the Volunteer Corps of Cavarly, when the following persons were duly elected: William McClellan, Captain Jacob Fisher, Jun'r, 1st Lieut. David Harris, 2nd Lieut David Cassat, Cornet About 40 have already joined, most of whom are completely equipped. Gentlemen who wish to become members of the Corps, are requested to apply to any of the officers. York, July 18, 1798." Captain McClellan and his brother in law, Samuel Spangler, owned and operated the Stage Coach Line from York to Lancaster and to Baltimore.