The Assembly act of 1739 divided the county into 8 nearly equal electoral districts:

• Chester - Aston, Chichester, Chester, Middletown, Edgmont
• Crum Creek - Easttown, Radnor, Newtown, Upper and Lower Providence
• Darby Creek - Haverford, Marple, Springfield, Darby and Ridley
• Brandywine - East and West Bradford, Concord, Birmingham, Thornbury, Bethel, Newlin
• Pickering - Charlestown, Tredyffrin, Whiteland, Goshen, Willistown, Westtown
• Red Clay Creek - East and West Marlborough, New Garden, Kennet, Fallowfield, Sadsbury
• Elk River - East and West Nottingham, New London, Londondery, London Britain, Londongrove, Oxford
• French Creek - East and West Caln, Nantmell, Coventry, Vincent, Uwchlan and Pikeland

An election was held in each township 4 days before the general election, to select one person well acquainted with the estates and circumstances of the inhabitants, the names so chosen in all the twps to be delivered to the sheriff, who should lot draw one name from each of the 8 districts to serve as inspectors at the general election.  The electors were required to own 50 acres of land, well seated, and with 12 thereof cleared and improved, or otherwise be worth 50 £ in money.

In 1766 the number of inspectors was increased to one from each township, not less than 4 nor more than 6 of whom were to be placed together at one window, door or other convenient place of the house where the election should be held.