In prehistoric times Ohio was the home of Indians known as Mound Builders. When the French first settled in Canada in the early 17th century, the Erie Indians were living south of Lake Erie, but in mid-century they were conquered and dispersed by the Iroquois. The Ohio River was discovered by the French, probably by La Salle on his trip of 1669.

Important dates in Ohio
c. 1670 The French explorer Rene-Robert Cavelier, Sieur de La Salle, probably was the first white man to reach the Ohio region.
1747 The Ohio Company of Virginia was organized to colonize the Ohio River Valley.
1763 France surrendered its claim to the Ohio region to Britain.
1787 The Northwest Territory was established.
1788 The first permanent white settlement in Ohio was established in Marietta.
1795 Indian wars in the Ohio region ended with the Treaty of Greenville.
1800 The Division Act divided the Northwest Territory into two parts, and Chillicothe became the capital of the new Northwest Territory.
1803 Ohio became the 17th state on March 1.
1813 Commodore Oliver H. Perry's fleet defeated the British in the Battle of Lake Erie.
1832 The Ohio and Erie Canal was completed.
1836 The Ohio-Michigan boundary dispute was settled.
1845 The Miami and Erie Canal was completed.
1870 Benjamin F. Goodrich began the manufacture of rubber goods in Akron.
1914 Ohio passed the Conservancy Act after floods in 1913.
1922 The Miami River Valley flood-control project was finished.
1938 The flood-control project in the Muskingum River Valley was completed.
1955 The Ohio Turnpike was opened to traffic.
1959 Terms of the governor and other high state officials were increased from two years to four.
1967 Ohio voters approved a plan for reapportionment of the state legislature.
1971 Ohio adopted an income tax.
1993 Ohio voters approved the sale of $200 million worth of bonds to finance improvements and expansion in the state's parks and other recreation areas.
2003 Ohio celebrated its bicentennial.