In December 1834, he joined a meeting of friends at the home of his brother, John Bullen Jr., in Hannibal, New York, to discuss the prospect of emigrating west to the new territories.
A subsequent meeting was held in February 1835, in which the Bullens and others agreed to form the "Western Emigration Company" to fund a project to travel west and purchase land.
The committee initially attempted to establish a purchase at the mouth of the Root River—at the site of the present city of Racine, Wisconsin—but were unable to come to terms with the current inhabitants of the area, led by Gilbert Knapp.
The Bullens settled on a spot just south of the Root River at the mouth of the Pike Creek, and began claiming land.
[1] That same summer, two adventurers, Samuel Resique (or Resseguie) and John Noble, arrived at the settlement intent on making speculative land claims.
[1] Tensions persisted, however—most of the settlers from the Western Emigration Co. became part of a temperance society, Resique used his piece of the island to set up the first tavern in the village.
[1] Most religious services in the settlement were held at the home of William Bullen, on Washington Island, until a schoolhouse was constructed in the Fall of 1837.
His father, John Bullen III, had served in the Massachusetts militia in the American Revolutionary War and afterwards was involved as a captain in Shays' Rebellion.
Julia was the daughter of Orris Hart, a New York politician and judge who had served several years on the Erie Canal Commission.