Question: Jim Lane's Fort, sometimes called Fort Jim Lane, was built in August 1856 in Holton, Kansas, it was named to honor free-state leader James H. Lane, who helped organize the settlement of several towns in northeast Kansas Territory, including Holton, James Henry Lane, also known as Jim Lane, (June 22, 1814 – July 11, 1866) was a partisan during the Bleeding Kansas period that immediately preceded which event?
Context: Fort Titus was built about April 1856 to be the fortress home of Henry T. Titus.  Titus was a colonel in the militia of the southern-oriented government of Kansas Territory.  It was said Titus squatted on the claim of a free-state settler while he was away and built his cabin on this land.  Fort Titus was a fortified log cabin with gun loopholes built into its walls to allow it to be defended from the inside.  This fort had at least one window and it had a small log addition on the north side that served as a kitchen. Jim Lane's Fort, sometimes called Fort Jim Lane, was built in August 1856 in Holton, Kansas.  It was named to honor free-state leader James H. Lane, who helped organize the settlement of several towns in northeast Kansas Territory, including Holton.  Holton was settled by about fifty free-state settlers at the time the fort was built.  The fort, built to serve as a place of refuge for the townspeople, was built of logs.  It measured 20 ft by 30 ft . The Marais des Cygnes massacre ( , , or ) is considered the last significant act of violence in Bleeding Kansas prior to the outbreak of the American Civil War.  On May 19, 1858, approximately 30 men led by Charles Hamilton, a Georgian native and proslavery leader, crossed into the Kansas Territory from Missouri.  They arrived at Trading Post, Kansas, in the morning and then headed back to Missouri.  Along the way they captured 11 Free-Staters, none of whom were armed and, it is said, none of whom had participated in the ongoing violence.  Most of the men knew Hamilton and apparently did not realize he meant them harm.  These prisoners were led into a defile, where Hamilton ordered the men to shoot.  He even shot and fired the first bullet himself.  Five men were killed. New Georgia's Fort was located in Miami County, Kansas, southeast of Osawatomie.  During the partisan warfare in Kansas Territory in 1856, a colony of southerners, possibly all Georgians, established New Georgia.  This colony was located on the Marias des Cygnes River.  A blockhouse fort was constructed there and entrenchments were begun but the fort destroyed before the entrenchments could be completed.  Northern settlers in the area claimed settlers at New Georgia harassed them.  In reality, some settlers from both the north and south had groups who caused trouble with their neighbors. The Siege of Lawrence occurred on May 21, 1856, when pro-slavery activists attacked and ransacked the town of Lawrence, Kansas, which had been founded by anti-slavery settlers to help ensure that Kansas would become a "free state".  The incident made worse the guerrilla war in Kansas Territory that became known as Bleeding Kansas. John Allen Wakefield and his family was one of the first settlers to come to the newly created Kansas Territory.  Free soilers, they arrived in western Douglas County, Kansas, in July 1854, one month after the territory was opened to settlement.  They built a large log house to serve primarily as their living quarters.  It had six rooms and was 6 mi west of the free-state stronghold of Lawrence, Kansas.  For protection the family built loop holes for guns into the sides of the house. Lane University was a college located in Lecompton, Kansas.  It was founded in 1865 by Rev. Solomon Weaver, the first president, and was named after U.S. Senator James H. Lane.  Jim Lane was a main free-state leader, and Lecompton was previously the capital of the opposing pro-slavery faction.  Local tradition notes that a funding drive to construct the university promised to name it after the major contributor.  Allegedly, James H. Lane made the largest pledge, received the namesake honor, and then died of a self-inflicted gunshot wound before he could carry out his promise. The Lecompton Constitution was the second of four proposed constitutions for the state of Kansas (it was preceded by the Topeka Constitution and was followed by the Leavenworth and Wyandotte Constitutions, the Wyandotte becoming the Kansas state constitution).  The document was written in response to the anti-slavery position of the 1855 Topeka Constitution of James H. Lane and other free-state advocates.  The territorial legislature, consisting mostly of slave-owners, met at the designated capital of Lecompton in September 1857 to produce a rival document.  Free-state supporters, who comprised a large majority of actual settlers, boycotted the vote.  President James Buchanan's appointee as territorial governor of Kansas, Robert J. Walker, although a strong defender of slavery, opposed the blatant injustice of the Constitution and resigned rather than implement it.  This new constitution enshrined slavery in the proposed state and protected the rights of slaveholders.  In addition, the constitution provided for a referendum that allowed voters the choice of allowing more slaves to enter the territory. In August 1856 Camp Sacket, a U.S. Army post, was about a mile away from Fort Titus.  Fort Saunders, some distance south of Fort Titus, was destroyed by free-state partisans on August 15, 1856.  Fort Titus was attacked the next day.  This was the Battle of Fort Titus.  About 400 free-staters under the command of Samuel Walker attacked Fort Titus.  Titus had a force of at least twenty-one men, including thirteen German stonemasons from nearby Lecompton, Kansas, with him.  The attack was launched before a brass cannon had arrived on the site.  This attempt was unsuccessful and the leader of this first attack was killed.  Apparently some of the men from this attack placed themselves between Lecompton and the Army troops, so no messages could be sent between Wilson Shannon, the governor, and the troops. James Henry Lane, also known as Jim Lane, (June 22, 1814 – July 11, 1866) was a partisan during the Bleeding Kansas period that immediately preceded the American Civil War.  During the war itself, Lane served as a United States Senator and as a general for the Union.  Although reelected as a Senator during 1865, Lane committed suicide the next year.
Answer: American Civil War