Question: Who was killed during the Kansas Territory skirmish of November and December 1855?

Context paragraphs:
Fifty-Niner: A "Fifty-Niner" is the term used for the gold seekers who streamed into the Pike's Peak Country of western Kansas Territory and southwestern Nebraska Territory in 1859.  The discovery of placer gold deposits along the South Platte River at the foot of the Rocky Mountains in northwestern Kansas Territory by a party of miners led by William Greeneberry "Green" Russell in July 1858 precipitated the Pike's Peak Gold Rush.

Barber County, Kansas: Barber County (county code BA) is a county located in the south-central portion of the U.S. state of Kansas.  As of the 2010 census, the county population was 4,861.  Its county seat and most populous city is Medicine Lodge.  It was named for Thomas Barber, an abolitionist who was killed in Douglas County in 1855 during the Wakarusa War.

State of Missouri v. Celia, a Slave: State of Missouri v. Celia, a Slave was an 1855 murder trial held in the Circuit Court of Callaway County, Missouri, in which an enslaved woman named Celia was tried for the first-degree murder of her owner, Robert Newsom.  Celia was convicted by a jury of twelve white men and sentenced to death.  An appeal of the conviction was denied by the Supreme Court of Missouri in December 1855, and Celia was hanged for her crime on December 21, 1855.

George Townshend, 3rd Marquess Townshend: George Ferrars Townshend, 3rd Marquess Townshend (13 December 1778 – 31 December 1855), known as Lord Ferrers of Chartley from 1782 to 1807 and as Earl of Leicester from 1807 to 1855, was a British peer.

Pawnee, Kansas: Pawnee is a ghost town in Geary County, Kansas, United States, which briefly served as the first official capital of the Kansas Territory in 1855.  Pawnee was the territorial capital for exactly five days – the legislature met there from July 2 to July 6 – before legislators voted to move the capital to Shawnee Mission, which is located in present-day Fairway.  It may be the shortest-lived capital of any U.S. state or territory (Colorado City also served as the capital of the newly established Colorado Territory for five days in 1862 but was not federally recognized).

Topeka Constitution: The Topeka Constitutional Convention met from October 23 to Nov 11, 1855 in Topeka, Kansas Territory at Constitution Hall.  It drafted the Topeka Constitution that would have banned slavery in Kansas.  The convention was organized by Free-Staters to counter the pro slavery Territorial legislature elected March 5, 1855 in polling suffering widely from electoral fraud and the intimidation of free state settlers.

Constitution Hall (Topeka, Kansas): Constitution Hall, in Topeka, Kansas, is one of the most famous buildings dating from the history of early Kansas.  It was a two-story building constructed between April and October 1855 of native limestone with a flat roof on the 400 block of Kansas Avenue, then in the center of Topeka's downtown, by brothers Loring and John Farnsworth.  It remained uncompleted for a period.  After its walls were plastered in October, those opposed to introducing slavery into Kansas Territory met in what became the Topeka Constitutional Convention which opened October 23, 1855.

Wakarusa War: The Wakarusa War was a skirmish that took place in Kansas Territory during November and December 1855 as part of the Bleeding Kansas violence.  It centered on Lawrence, Kansas, and the Wakarusa River Valley.

Charles Hotham: Sir Charles Hotham, KCB, RN (14 January 180631 December 1855) was Lieutenant-Governor and, later, Governor of Victoria, Australia from 22 June 1854 to 10 November 1855.

New England Emigrant Aid Company: The New England Emigrant Aid Company (originally the Massachusetts Emigrant Aid Company) was a transportation company in Boston, Massachusetts, created to transport immigrants to the Kansas Territory to shift the balance of power so that Kansas would enter the United States as a free state, rather than a slave state.  Created by Eli Thayer in the wake of the Kansas-Nebraska Act, which allowed the population of Kansas Territory to choose whether slavery would be legal, the Company is noted less for its direct impact than for the psychological impact it had on proslavery and antislavery elements.  Thayer's prediction that the Company would eventually be able to send 20,000 immigrants a year never came to fruition, but it spurred Border Ruffians from nearby Missouri, where slavery was legal, to move to Kansas to ensure its admission to the Union as a slave state.  That, in turn, further galvanized Free-Staters and enemies of Slave Power.

Supporting paragraphs: Barber County, Kansas Wakarusa War
Answer: Thomas Barber