He was the firebrand preacher who lit up the antagonisms the year before with the so called Mormon Reformation
http://en.wikipedia.org/wiki/Jedediah_M._Granthttp://en.wikipedia.org/wiki/Mormon_ReformationMMM is simply the most well known of the Mormon murders.
The states did not forcebly remove the mormons from anywhere. This is one of the great lies of Mormonism. They were forced to leave because they were apart of a full blown criminial consipiracy and the enforcement of laws engangered their freedom.
For example the death of Smith is seen as a mob that picked him out for no reason.
Joseph Smith led an attack on the newspaper the Nauvoo Expositor
http://en.wikipedia.org/wiki/Nauvoo_Expositor. It was a newspaper that in its first edition was going to expose the lies and crimes of Joseph Smith.
Who were the editors and owners of this newspaper? anti mormon bigots? no. Joseph Smith's longest and most trusted associate William Law. As they say "no man or set of man are more acquainted with its rise". They even preached the that the book of Mormon was true, but that Smith is " a wolf in sheeps' clothing"
What is it that they allege? That Smith coerced young foreign born woman who were new recruits to have sex and that some of them were so traumatized by it that they went into depression and died. Young orphans have been forced into early marriages.
The paper's criticism of Smith was focused on three main points: (1) the opinion that Smith had once been a true prophet, but had become a fallen prophet because of his introduction of plural marriage, exaltation and other controversial doctrines; (2) the opinion that as church president and Nauvoo mayor, Smith held too much power and desired to create a theocracy (see also Council of Fifty, Theodemocracy); and (3) the belief that Smith was corrupting young women by forcing, coercing or introducing them to the practice of plural marriage.
Law was head of the First Presidency, the top mormon who witnessed Smiths criminal conspiracies.
Smith used his influence to have the town order the destruction of the newspaper. Angry mobs then reacted to this dictatorial use to further Smith's criminal acts and sought to bring him to justice. Smith had escaped but in his tremendous arrogance and hubris returned and was then captured and came under mob justice, most unfortunately because a trial would have established a record of his crimes and he would have died completely exposed for the con man that he was.
As for the settlers who travelling to California who may have had hard feelings for the Mormons many of them had lost their life savings in Joseph Smith's Ponzi scheme Kirtland Safety Society
http://en.wikipedia.org/wiki/Kirtland_Safety_SocietyEven though they were repeatedly denied a bank charter they established this limited liability company and then issued stocks that had the words "Kirtland Safety Society anti-Bank-ing Company" except that "anti" and "ing" were in tiny print making it seem that they were bank stocks.
A small effort? Hardly - the capitalization of this fraudulent bank was equal to nearly 50% of the capitalization of all of the banks in the State of Ohio.
Smith was the head of a large criminal conspiracy. That conspiracy was involved in political, economic and sexual crimes, not unlike those that have resulted in the imprisonment of the Fundie Mormon Church last year.
Smith's main accusers were not from the outside world, but those that were in the most trusted senior positions of the mormon church. Contemporary Mormons who talk of Religious persecution are knowing liars, because the key points of mormon history, including the role of Law and others is taught in Mormon history classes. Mormons know that they have been involved in crimes from the beginings and that the main reasons for them leaving IL and Ohio was because of breakaway groups of senior mormons tried to pressure civilian authorities to hold Smith accountable for his crimes.