The Manchester Observer was formed in January 1818 by a group of radicals that included John Knight, James Wroe and John Saxton. Within twelve months the newspaper was selling 4,000 copies a week. It has been argued that the newspaper pioneered popular journalism with its racy style aimed at an literate working-class.
Although the newspaper started as a local paper, by 1819 it was sold in most of the large towns and cities in Britain. Henry Hunt called the Manchester Observer "the only newspaper in England that I know, fairly and honestly devoted to such reform as would give the people their whole rights."
Despite its sales figures, the Manchester Observer was always in financial difficulties. The owners had problems persuading local businesses to advertise their goods in the newspaper. Most weeks, advertisements made up only one of its twenty-four columns.
Journalists working for the newspaper were constantly being sued for libel. Several of their journalists, including John Wroe, John Saxton and T. J. Evans had been sent to prison for articles they had written criticizing the government.
In March 1819, three of the men involved in the Manchester Observer, Joseph Johnson, John Knight and James Wroe formed the Patriotic Union Society. All the leading radicals in Manchester joined the organisation. Johnson was appointed secretary of the Society and Wroe became treasurer. The main objective of the Patriotic Union Society was to obtain parliamentary reform and during the summer of 1819 it decided to invite Henry Orator Hunt to speak at a public meeting in Manchester. The men were told that this was to be "a meeting of the county of Lancashire, than of Manchester alone. I think by good management the largest assembly may be procured that was ever seen in this country."
James Wroe, the editor of the Manchester Observer, was at the St. Peter's Field and described the attack on the crowd in the next edition of the newspaper and is believed to be the first person to describe the incident as the Peterloo Massacre. Wroe also produced a series of pamphlets entitled The Peterloo Massacre: A Faithful Narrative of the Events. The pamphlets, which appeared for fourteen consecutive weeks from 28th August, price twopence, had a large circulation, and played an important role in the propaganda war against the authorities. The government wanted revenge and James Wroe was arrested and charged with producing a seditious publication. He was found guilty and sentenced to twelve months in prison, plus a £100 fine.
With the arrival of the Manchester Guardian in 1821 the Manchester Observer decided to cease publication. In its last edition, the editor wrote: "I would respectfully suggest that the Manchester Guardian, combining principles of complete independence, and zealous attachment to the cause of reform, with active and spirited management, is a journal in every way worthy of your confidence and support."