John Bratton, a powerful Whig who owned a printing business that was in danger of losing government contracts, alleged in his newspaper that McGowan had accepted bribes to support a rival bid.

[4] Appointed as superintendent of police in Moyamensing, McGowan became embroiled in yet another controversy when he was implicated in a robbery and convicted in October 1848 on dubious evidence by a judge who, according to Donald Hauka, was either a Whig or a personal enemy.

In San Francisco he began a career running a roulette wheel on the second floor of a brothel,[6] and made friends with David Broderick, a powerful Tammany Hall Democrat of the northern Irish-Catholic "The Boys" faction.

An outbreak of arson, attributed to San Francisco's merchants hoping to convert a surplus of low-priced goods into insurance claims,[7] created a groundswell of public clamour for the imposition of "law and order" to rid the town of the criminals thought to be behind the devastating fires.

The Sunday Times, published by a former Democrat turned Know-Nothing named James Casey, fanned the problem by including a defamatory insert attacking King of William's brother Tom and the morals of his wife, signed "Caliban", a pen-name known to be used by McGowan.

Eventually his friends managed to have a special act passed in the California legislature to enable him to be tried in the Napa Valley, far enough away from San Francisco to ensure a fair jury.

Upon his arrival McGowan met in the street a member of the San Francisco Vigilance Committee (who tried to shoot him) and the colonial governor who warned him that he needed to obey Her Majesty's laws while in British territory.

Once on the mainland, in the newly created Colony of British Columbia, McGowan met up with Democrat friends and sympathizers at Hill's Bar, while the Vigilance Committee members gathered around the settlement at Yale up river.

It wasn't long before McGowan was in trouble with the law (another fight, with Dr. Max Fifer, a Vigilance Committee member) and implicated in sheltering a man wanted for murder of a British subject at Yale.

This was accomplished in relatively short order, and without bloodshed, although McGowan's supporters at Hill's Bar did fire upon the Royal Engineers as they made their way up the Fraser River to Yale.

In 1859, tired of struggling against the numerous Vigilance Committee miners on the Fraser, McGowan sold his stake at Hill's Bar for $500 and left British Columbia with $5,000 in gold dust.