Jan. 1, 1855 - Hon. S. D. Lecompte, Chief Justice of the Territory of Kansas, arrived in Leavenworth.
Feb. 12, 1855 - The first birth in Oskaloosa was that of Mary E., daughter of Mr. and Mrs. Thomas H. Noble, on this date.
Feb. 20, 1855 - The first convention in Linn county was held at Sugar Mound for the purpose of nominating candidates for the Territorial Legislature
March 6, 1855 - The first post office was opened in the city of Leavenworth, by Postmaster Lewis N. Reese, in his store at the corner of Delaware street and the Levee.
Mar. 30, 1855 - In the election on this date, Border Ruffians were key to electing a pro-slavery Territorial Legislature
Apr. 10, 1855 - The first post office in Atchison was established, with Robert S. Kelley as postmaster. It was opened in a small building later occupied by the Otis house.
May 14, 1855 - The officers of the Lecompton Town Company reported that the town site, which consisted of 600 acres, had been surveyed by D. H. Harting with the design and intention of making Lecompton not only a large city but also the capital of the state.
May 16, 1855 - The buildings of the military Fort Scott, erected by the Government at a cost of about $52,000, were sold at auction to private civilian bidders.
May 21, 1855 - Sheriff Samuel J. Jones entered Lawrence with a large group of armed men, destroying two newspapers, damaging the Fee State Hotel, and looting other businesses.
Jun. 8, 1855 - The Fort Scott Town Company was initially organized.
Jun. 8, 1855 - The first Free-state convention was held in Lawrence on the evening of this date.
Jun. 25, 1855 - The Baptist Church was formed in Lawrence, and included the following persons: J. S. Emery, M. M. Hammond, S. Jones, Rebecca W. W. Jones, W. F. Herrick, Lydia A. Herrick, Elizabeth Parks. They worshiped in the private homes of the members for several months, and then in more public rooms and halls as they could secure them.
August 30, 1855 - The City of Atchison was incorporated. The corporation was granted the privilege of holding land “not to exceed 640 acres” and the stock of the company was to be regarded as personal property.
Aug. 31, 1855 - The county commissioners of Atchison County were elected by the territorial legislature, with Gov. Woodson signing their commissions.
Sep. 18, 1855 - Doniphan County was officially organized on this date.
Oct. 1, 1855 - The first marriage solemnized in the Geary County was on this date between Thomas Jenkins and Ella Wicks.
Oct. 23, 1855 - The Free-state Constitutional Convention assembled at Topeka.
Nov. 25, 1855 - The first marriage in Jefferson County was performed, that of Alfred Corey and Miss Martha Hoovey, who were married as Osawkie by Elder William Hicks.
Dec. 1, 1855 - A small army, composed mainly of Border Ruffians, laid siege to Lawrence, Kansas, in the nearly bloodless climax to the "Wakarusa War."
Dec. 6, 1855 - Thomas W. Barber, a Free-State settler in Douglas County, was killed near Lawrence, Kansas members of the slavery faction from Missouri. Barber County, Kansas was named in his honor.
Dec. 15, 1855 - The Topeka Constitutional Convention, the first effort to establish Kansas under a state constitution, met and ratified the Topeka Constitution.
Dec. 21, 1855 - A. J. Whitney was appointed postmaster for Grasshopper Falls, now called Valley Falls.
Dec. 25, 1855 - Cyrus Shaw opened a store in the fourth building built in Paola.
1855 - The first newspaper is published at Fort Scott, and the first in Bourbon County, called the Southern Kansas.