Leavenworth, the county seat of Leavenworth county and the fourth largest city in the state, is situated in the eastern part on the Missouri river, 27 miles above Kansas City. The city had its origin at a meeting at Weston, Mo., a few days after the passage of the Kansas-Nebraska bill. On June 12, 1854, the town site was marked off by George W. Gist, John C. Gist and Samuel Farnandis on the Delaware trust lands immediately south of Fort Leavenworth military reservation, the squatters there agreeing to relinquish their rights to the town association, which was formed on June 13. George W. Gist was elected president; H. Miles Moore, secretary; Joseph B. Evans, treasurer; L. D. Bird, Amos Rees and E. A. Ogden, trustees; L. D. Bird, O. Diefendorf and H. Miles Moore, committee on by-laws. The town site of 320 acres was platted into lots and the property was divided into 175 shares, each of the 32 members of the association receiving 5 shares, 12 lots to each share, and the remaining 15 shares were to be held by the trustees to be used for the best interests of the town.

The first sale of town lots was held Oct 9, 1854, when lots were sold anywhere on the town site, but with the understanding that they were for immediate improvement. The Indians viewed with dissatisfaction the encroachment of the whites upon their lands, and stirred up by emissaries from the rival city of Atchison, sent a petition to the government praying that something be done in regard to the squatters. As a result the government issued an order to the troops at the fort to drive the settlers off, but the founders of Leavenworth had the order delayed and upon assuring the Delaware chiefs that they would pay the price fixed by the government were allowed to stay.

One of the first buildings in Leavenworth was the saw-mill of Murphy & Scruggs, at the mouth of Three Mile creek, where much of the lumber was cut for the buildings of the new town. The Leavenworth Hotel was opened in the fall. On Oct. 8, W. C. Capels, an elder of the Methodist church, held the first religious service in the town under the shade of a tree. By Jan. 1, 1855, there were 200 inhabitants. On March 6, the postoffice was opened.

Leavenworth was incorporated by an act of the legislature in the summer of 1855, and an election fixed for Sept. 3, at which time Thomas W. Slocum was elected mayor; J. H. Day, Frederick A. Emory, Thomas H. Doyle, A. Fisher, G. J. Park, William T. Marvin, councilmen. The council met first on Sept. 11, 1855, in a room over a store on Main street near Delaware. Dr. J. H. Day was chosen president of the council and S. J. Anthony clerk. William A. McDowell was chosen as marshal; John I. Moore, attorney; William H. Bailey, treasurer; H. G. Weibling, assessor; E. L. Berthoud, surveyor, and M. L. Truesdell, comptroller. The council adopted the by-laws of the city of Muscatine, of 1853, as a form of government. The fire company of the city was organized under a charter granted by the legislature in the fall of 1855.

On July 5, 1858, a disastrous fire occurred. Starting in the theater on the corner of Third and Delaware streets, it swept away a large part of the business district, and for a time it looked as though the whole city would be wiped out.

The early commercial development of Leavenworth was rapid, as it became the starting point of the great government overland transportation company owned and operated by Majors, Russell & Company. This brought stores, and a business life that would not have come in years, in the natural course of events. The Salt Lake and California traders also changed their starting point from the Missouri points to Leavenworth. The great number of employees of these freight companies and the transient population demanded more hotel accommodations. This led to the erection of the Planters' Hotel, completed in the fall of 1856, which became one of the most famous hostelries on the Missouri river. By this time the town had a population of about 1,200, but the political disturbances of 1856 rather hindered commercial development. With the growth of the town means of communication became imperative. There were two great military roads from Fort Leavenworth, one which joined the emigrant road at Whitfield City, and a second known as the Oregon and California road. Roads were laid out to connect Leavenworth with towns up and down the river, and to Lawrence, Lecompton and Topeka; hack and mail lines were established, making weekly and tri-weekly trips to towns of importance in the territory; the telegraph line was extended from St. Louis to Leavenworth in June, 1859, and the following spring the Pike Peak express line began to run from Leavenworth to Salt Lake. The first railroad to come near Leavenworth was the Atchison & St. Joseph, which was completed to Weston in 1861, where it made connection with river transportation for Leavenworth. Two years later Leavenworth became a terminus of the Kansas Pacific railroad, connecting with the main line at Lawrence. With the passing years most of the important lines have built to Leavenworth until in 1911 service was provided by the Union Pacific, Missouri Pacific, Atchison, Topeka & Santa Fe, Chicago, Rock Island & Pacific, Chicago, Burlington & Quincy, Leavenworth, Kansas & Western, and the Kansas City-Leavenworth electric line which connects those cities.

By 1859 the streets of Leavenworth were graded, sidewalks were laid, and gas works constructed. The population at that time was over 5,000.

In 1855 a small building near the levee was rented by a Lutheran minister for religious purposes. The first school in the community was taught by H. D. McCarty. The first school board of the city was organized in July, 1858, a house was rented and a teacher hired. In the fall the city was divided into school districts. Today Leavenworth has an excellent public school system. Besides the excellent public schools several sectarian and private schools are maintained in the city.

The Catholic diocese of Leavenworth was established in 1851. Bishop Miege said the first mass in the town in 1854, and the Cathedral of the Immaculate Conception was erected in 1863. The First Presbyterian Church, the first white church of this denomination in Kansas, was organized in Jan., 1856. In November of the same year St. Paul's Episcopal parish was established. The United Presbyterian church was established in 1857, the First Congregational in March, 1858, and the Baptist church in the fall of the year. These pioneer organizations were followed by other denominations, so that today Leavenworth has as many and as fine churches an any city of its size in the state.

Leavenworth has an altitude of 772 feet and is admirably situated. Its manufactories are extensive—due to the splendid shipping facilities and the large supply of coal in the immediate locality. The chief products are mine and mill machinery, steam engines, stoves, wagons, shoes, bakers' ovens, pumps and implements. The city also has large bridge works, packing houses, flour mills, furniture factories, creameries, etc. It is also a jobbing point for a large territory. The streets are well paved, and the city is provided with an electric lighting system, electric street railways, waterworks, etc. Three miles north of the city is Fort Leavenworth (q. v.) which is connected with Leavenworth by the street railway. In 1910 there were 79 manufacturing establishments in the city employing 1,311 wage earners; $3,111,000 of capital was invested, and the net value of the products was $1,678,000, or an increase of seven per cent. in ten years. The population in 1910 was 19,363.