c. 2.5 billion years ago: Please refer to Jean C. Prior, Landforms of Iowa, Iowa City: University of Iowa Press, 1991. Chapter 2 is "Geologic Origins of Iowa Landforms" and Chapter 3 is "Landform Regions". These chapters explain in detail the geological entries on this time line. Ages of rock formation is normally given as an inclusive time period, but for purposes of clarity on the time line we have given only the beginning date of the time period. This annotation applies to all entries on the time line to that dated c. 5,000 years ago. Please note also that these dates are geological estimates, and are given as "years ago", not as B.C. or A.D. as historical dates are often given.

c. 12,000 years ago: Please refer to Lynn Marie Alex, Exploring Iowa's Past: A Guide to Prehistoric Archaeology, Iowa City: University of Iowa Press, 1980. Chapters 9 through 15 describe the characteristics of the various cultures mentioned in the time line. There are maps showing the locations of each, and illustrations showing artifacts used by each. Please note also that these dates are archaeological estimates, and are given as "years ago", not as B.C. or A.D. as historical dates are often given. For additional information, please see The Goldfinch, Volume 7, # 1 (September 1985), and The Palimpsest, Volume 42, # 4 (April 1961), Volume 50, # 5 (May 1969), and Volume 51, # 12 (December 1970.

1673: Joliet and Marquette explored for the King of France. They canoed down the Wisconsin River and then down the Mississippi River to the mouth of the Arkansas River. Upon the return to Montreal, Joliet's journal was lost when a canoe capsized, and our information about the expedition comes from Marquette's journal and map. They supposedly landed on the west bank of the Mississippi and met with some Native American Indians, and most people believe that site was near the mouth of the Iowa River. All the journal says is that it was near the mouth of a river. For additional information, please see The Palimpsest, Volume 54, # 3 (June 1973).

1682: LaSalle explored the Mississippi River from its mouth, and claimed the river and all land drained by it for the King of France. It is upon the claim of LaSalle that France claimed the interior of North America. Such means of making land claims, by planting a flag at the mouth of a river and claiming all land drained by that river and its tributaries, were common at the time. The area was known as Louisiana, after King Louis XIV of France.

1762: The King of France transferred the claim to the land described above to the King of Spain during the Seven Years' War, usually known in the United States as the French and Indian War. This was a device to prevent the land from being claimed by England, against whom the war was being fought, mostly over colonial land claims, but also over differences in Europe.

1785: The Land Ordinance created the mechanism by which new states could be admitted to the Union from the Old Northwest Territory, and also the methods to be used for surveying the undeveloped and unclaimed land. The so-called "Square mile survey" was later used in Iowa, and Iowa was admitted to the Union under the provisions of this act.

1788: Julien Dubuque is considered the first white person to live permanently in what is now Iowa. He and other French from Canada lived along Catfish Creek, under an agreement with the Mesquakies, whom they hired to do most of the actual mining work. Lead was a valuable commodity, and Dubuque sold most of it in units known as "pigs" in St. Louis, where most of it was used to make ammunition. For additional information, please see The Palimpsest, Volume 39 (1966), and Volume 57 (1976).

1796: Dubuque's land claim was confirmed by the Spanish colonial government at this time, but he had been in effective control of it since 1788. For additional information, please see The Palimpsest, Volume 39, # 1 (November 1958), Volume 51, # 1 (January/February 1976).

1799: Tesson's land claim was initially made at this time. He supposedly planted a grove of apple trees, and made other improvements to solidify his claim to the land which was in Lee County, near Montrose.

1800: During the Napoleonic wars in Europe, Spain became a satellite of France, and the Mississippi River area was transferred back to France under pressure from Napoleon. Spain had exerted very little control or contact with the area north of St. Louis.

1803: President Thomas Jefferson wished to purchase trading rights at New Orleans so that American products would have free navigation of the Mississippi River to ocean-going ships. When the opportunity arose to purchase the whole tract of land, he took advantage of it, but not without opposition from Congress and other people who felt that it was unconstitutional to add territory to the United States. Jefferson established a precedent with the Louisiana Purchase which led to later acquisition of other land which was added to the United States.

1803: For administration, the Louisiana Purchase was divided into the Upper and Lower Districts of Louisiana, with capitals at St. Louis and New Orleans respectively. This was mostly a paper transaction, because there were no legal permanent residents in the area except Native American Indians, and this administration did not apply to them.

1804: In another paper transaction, the District of Louisiana was created, with practical administration, of which there was none, assigned to the Territory of Indiana.

1804: The Lewis and Clark explorations were to make contact with the Native American Indians, chart flora and fauna, and investigate the economic resources. The party went up the Missouri River in 1804, camping on the "Iowa" side of the river several times. They held a council with the Indians on the west side of the river, providing the source of the name for the city of Council Bluffs.

1804: Sergeant Floyd died of appendicitis while camped just south of the present Sioux City. He was buried there, and later a tall obelisk was constructed and designated a National Historic Landmark. He is the first white American known to have been buried in what would become Iowa, and he is the only soldier to die on the Lewis and Clark expedition.

1804: Several members of the Sauk tribe were in St. Louis, but with no authority to act for the tribe in any treaties. The American authorities led these Indians to become intoxicated, and in this condition forced them to sign a treaty giving away tribal lands. This treaty should have had no legal standing, but the United States government later based land claims on it. This is also the beginning of the United States government mistake in referring to the "Sac and Fox" as one tribe, even though the Sauk were a distinct tribe and the other tribe is properly called

Mesquakie, not Fox. This error has perpetuated by the government until the present.

1805: Pike's expedition was ordered to investigate the Mississippi River above St. Louis, noting especially the rivers, prairies, islands, mines, quarries, timber, and Indian villages and settlements. He also designated two sites for future forts, but no fort was built in either place. He designated what is now Crapo Park in

Burlington, and what is now Pike's Peak State Park near McGregor. Pike later explored in the Rocky Mountain west where a peak in Colorado is named for him. For additional information, please see The Palimpsest, Volume 49, # 2 (February 1968).

1805: In yet another paper transaction, the upper Mississippi valley was named the Territory of Louisiana. As a part of this designation, the Spanish land grants to Dubuque, Tesson, and Giard were confirmed.

1806: In the trip back down the Missouri River, Lewis and Clark again camped on the "Iowa" side but made no further impact on the future state.

1808: Fort Madison was the first federal facility to be built in Iowa. When Fort Madison was constructed the army officer in charge used poor judgment in sitting it. The place had the Mississippi River on one side, a high bluff on another side, and a ravine on a third side. It was well nigh indefensible.

1812: When Louisiana was admitted to the Union as a state, the northern part of the Louisiana Territory was re-named Missouri.