IND 911.772 ATLA Indiana Atlas of Historical County Boundaries editied by John H. Long c1996 This Atlas makes it easy to follow the chronology of Indiana state boundaries and individual county boundaries within the state. The Indiana Atlas of Historical County Boundaries also includes many useful maps, a Table of County Creation dates, a Table of Censuses, and Census Outline Maps. On page 189 there is a chronology for Lake County, Indiana
- 15 February 1836 Lake county is fully organized and detached from Porter county.
First few enteries from the Consolidated Chronology of Indiana State and County Boundaries p.9
- June 2, 1609 King James I granted a new charter to the Virginia Company of London, expanding Virginia's jurisdiciton westward and northwestward to the Pacific Ocean; included all of present Indiana.
- February 10, 1763 Treaty of Paris, ending the Seven Years' War between Great Britan (the Victor) and France and Spain, formally transferred to the British all of Canada (territory north of the Ohio River-Great Lakes-St. Lawrence River line), including present Indiana, and implicitly set the Mississippi River as the new western limit for the British colonies
- May 20, 1774 The British Parliament passed the Quebec Act, placing all territory north and west of the Ohio River, including present Indiana, under the jurisdiction of the province of Quebec.
- July 4, 1776 The United States declareditself independent of Great Britain, implicitly opening the possiblility that Virginia and some other states might claim territory north of the Ohio River and west of the Appalachian Mountians based on their colonial charters.