Iowa was organized as a Territory by Act of June 12, 1838,
effective July 3, from a portion of Wisconsin Territory. The limits
were defined as follows in the Act1 creating it:
all that part of the present Territory of Wisconsin which lies west
of the Mississippi river, and west of a line drawn due north from the
headwaters or sources of the Mississippi to the Territorial line.
The approximate position of the outlet of Lake Itasca, which is
generally accepted as the source of the Mississippi, is latitude
47° 15 1/3', longitude 95° 12 1/2'. The river runs
north-westward for about 6 miles before it turns east. The
north-south boundary line across the western part of the Lake of the
Woods is in longitude 95° 09' 11.6" (p.14).
The following clause from an Act passed in 1839 is supplementary
to the Act above quoted:2
That the middle or center of the main channel of the Mississippi
shall be deemed, and is hereby declared, to be the eastern boundary
line of the Territory of Iowa, so far or to such extent as the said
Territory is bounded eastwardly by or upon said river.
On March 3, 1845, an Act was approved for the admission of Iowa to
the Union as a State, but the Act required that the assent of the
people of Iowa be given to it by popular vote. In this Act the
boundaries were given as follows:3
That the following shall be the boundaries of said State of Iowa,
to wit: Beginning at the mouth of the Des Moines River, at the middle
of the Mississippi, thence by the middle of the channel of that river
to a parallel of latitude passing through the mouth of the Mankato or
Blue-Earth river [latitude 44° 10'], thence west along the said
parallel of latitude to a point where it is intersected by a meridian
line, seventeen degrees and thirty minutes west of the meridian of
Washington city, thence due south{{ to the northern boundary line of
the State of Missouri, thence eastwardly following that boundary to
the point at which the same intersects the Des Moines river, thence
by the middle of the channel of that river to the place of beginning.
These boundaries were not acceptable to the people and by a
popular vote were rejected.
Another constitutional convention was held in May, 1846, and
Congress passed an Act, approved August 4, 1846, fixing the
boundaries in accordance with the wishes of the people and described
as follows:
Beginning at the middle of the main channel of the Mississippi
River at a point due east of the middle of the mouth of the main
channel of the Des Moines River; thence up the middle of the main
channel of the said Des Moines River to a point on said river where
the northern boundary line of the State of Missouri, as established
by the constitution of that State, adopted June twelfth, eighteen
hundred and twenty, crosses the said middle of the main channel of
the said Des Moines River; thence westwardly along the said northern
boundary line of the State of Missouri, as established at the time
aforesaid, until an extension of said line intersect the middle of
the main channel of the Missouri River, thence up the middle of the
main channel of the said Missouri River, to a point opposite the
middle of the main channel of the Big Sioux River, according to
Nicollet's map; thence up the main channel of the said Big Sioux
River, according to said map, until it is intersected by the parallel
of forty-three degrees and thirty minutes north latitude; thence east
along said parallel of forty-three degrees and thirty minutes, until
said parallel intersect the middle of the main channel of the
Mississippi River; thence down the middle of the main channel of said
Mississippi River to the place of beginning.
Iowa was finally declared admitted to full statehood by Act of
December 28, 1846.
The admission of Iowa appears to have left a large area to the
north and west unattached, which so remained until Minnesota
Territory was organized in 1849.
The Act of August 4, 1846, directed that a long-standing dispute
between Missouri and Iowa Territory regarding their common
boundary{{{ be referred to the United States Supreme Court for
adjudication. The area claimed by both was a strip of land about 10
miles wide and 200 miles long, north of the present boundary.
Missouri maintained that the clause in that state's enabling Act,
"the rapids of the river Des Moines," referred to rapids in the river
of that name and not to rapids of a similar name in the Mississippi,
also that the Indian boundary line run and marked in 1816 by
authority of the United States, known as the Sullivan line,{{{{ was
erroneously established. A line claimed by Missouri was run by J. C.
Brown in 1837 by order of the State legislature.
The United States Supreme Court decided in 1849 that the Sullivan
line of 1816 is the correct boundary and ordered that it be
resurveyed. The report of the commissioners appointed by the court to
re-mark the line was accepted in 1851.
So many of the marks on this line as established in 1850 had
become lost or destroyed that the United States Supreme Court in 1896
ordered that certain parts be re-established, especially those
between mileposts 50 and 55. Accordingly 20 miles of line was
resurveyed by officers of the United States Coast and Geodetic Survey
in 1896, and durable monuments of granite or iron were established
thereon. The geographic position of milepost No. 40 was determined as
latitude 40° 34.4', longitude 95° 51', and that of No. 60 as
latitude 40° 34.6', longitude 93° 28'.
The survey of the north boundary of Iowa on the parallel of 43°
30', authorized by congressional Act of March 3, 1849, was completed
in 1852. The position for each end of the line and for several
intermediate points was determined astronomically.
This is the first State thus far noted having a boundary referred
to the Washington meridian. Congress by Act approved September 28,
1850, ordered:
That hereafter the meridian of the observatory at Washington shall
be adopted and used as the American meridian for all astronomic
purposes and { { { Greenwich for nautical purposes.
15 Stat. L. 235.
25 Stat. L. 357.
35 Stat. L. 742.
{Reprinted from "Geological Survey Bulletin 817."
{{This north-south line is a few miles west of the city of Des
Moines.
{{{The northern boundary of Missouri had been established as "100
miles north of the junction of the Missouri and Kaw (Kansas) rivers
and thence east { { {." (See 7 Howard 660 and 10 Howard 1.)
{{{{Sullivan had disregarded the changing declination of his
compass as he proceeded east; hence the southern boundary of Iowa is
a curve. The following is a quotation from the commissioner's records
as reported in 10 Howard (U.S.) 1,5: "We soon satisfied ourselves
that the line run by Sullivan was not only not a due east line, but
that it was not straight. That more or less northing should have been
made in the old line was to have been expected from the fact that
Sullivan ran the whole line with one variation of the needle, and
that variation too great. This would account for the fact that the
northing increases as he progressed east."