Dulany, along with two older brothers (William and Joseph) landed at Port Tobacco, and became indentured to Colonel George Plater II for a three-year period.

Lord Baltimore vetoed a bill in 1722 which the General Assembly had passed in order to bring the colony fully under all English statute law.

Dulany led protests against this, writing a pamphlet in 1728 entitled "The Right of the Inhabitants of Maryland, to the Benefit of the English Laws".

[6] In 1736 Ogle dispatched Dulany to Philadelphia in order to negotiate the release of a number of imprisoned Marylanders, though without success, and the border warfare continued.

He advertised for tenants to settle his land in Baltimore, Kent and Prince Georges county, paying with tobacco, corn or wheat.

[2] After his death, in 1754, Dulany's third wife, Henrietta Maria, appeared before Michael MacNamara, then Deputy Commissioner of Anne Arundel County, seeking to overturn the will of her late husband.