Question: The Lecompton Constitution was preceded by a constitution drafted during a convention organized by who?

Context paragraphs:
Argentine Constitution of 1819: The Argentine Constitution of 1819 was a Constitution drafted by the Congress of Tucumán in 1819.  It was promoted by Buenos Aires but rejected by the other provinces and did not come into force.

Constitution Hall (Lecompton, Kansas): Lecompton Constitution Hall, also known as Constitution Hall, is a building in Lecompton, Kansas that played a role in the long-running Bleeding Kansas crisis.  It is operated by the Kansas Historical Society as Constitution Hall State Historic Site.

English Bill: The English Bill was drafted on April 23, 1858, it was an offer made by the United States Congress to Kansas Territory.  Kansas was offered some millions of acres of public lands in exchange for accepting the Lecompton Constitution.

Lecompton Constitution: 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.

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.

QC Anime-zing!: QC Anime-zing!  is an anime convention organized in the Quad Cities.  The convention offers anime screenings, video games, a dealers room, guest panels, fan panels, cosplay competitions, and many other events typical of an anime convention.  It was first held at The Lodge Hotel in Bettendorf, IA from June 18–20, 2010.  Guests for the 2010 convention were Johnny Yong Bosch, Robert Axelrod, Spike Spencer, Eyeshine, and The Man Power.  The 2011 convention will be held June 17–19, 2011 at The RiverCenter in Davenport, Iowa.

Ecuadorian constitutional referendum, 1869: A constitutional referendum was held in Ecuador on 1 July 1869 to ratify or reject the constitution drafted by the Ecuadorian Constituent Assembly elected earlier in 1869.  The country's eighth constitution, known as the Black Charter, was approved by 13,640 of the 14,154 voters.

Massachusetts Constitutional Convention of 1778: The Constitutional Convention of 1778 was the first constitutional convention held in Massachusetts to draft a new state constitution following the state's declaration of independence in 1776.  The convention that drafted the proposed constitution was composed of the elected members of the Massachusetts Provincial Congress and the Governor's Council meeting as a single body.  The document drafted by this convention was approved in February 1778, and submitted to the voters of the state for ratification, the first constitution to be submitted for such a vote.  It was soundly rejected by voters, leading to a second convention in 1779, whose proposed constitution was accepted.

New England Non-Resistance Society: The New England Non-Resistance Society was an American peace group founded at a special peace convention organized by William Lloyd Garrison, in Boston in September 1838.  Leading up to the convention, conservative members of the American Anti-Slavery Society and the American Peace Society expressed discomfort with Garrison's philosophy of "non-resistance" and inclusion of women in public political activities.  After conservative attendees opposing Garrison walked out of the convention in protest, those remaining formed the "New England Non-Resistance Society".

Ecuadorian constitutional referendum, 2008: A constitutional referendum was held in Ecuador on 28 September 2008 to ratify or reject the constitution drafted by the Ecuadorian Constituent Assembly elected in 2007.  The new constitution was approved by 69% of voters.

Supporting paragraphs: Lecompton Constitution Topeka Constitution
Answer: Free-Staters