Winding westward from Montana's State Capitol building to the city's Lewis and Clark Library, State Street in Helena, Montana is these days just a humdrum suburban avenue. But 150 years ago it was the centre of one of the most profitable red light districts in the Old West. And the madam who ruled the roost there was an illiterate Irishwoman.

Mary Welch was born in Ireland in 1844. At 14 she emigrated with her family to New York, where Mary was put to work in a brutal sweatshop. In those days there were two established routes for uneducated women seeking to escape poverty. One was to marry a rich man. The other was prostitution. To Mary's way of thinking, those options weren't very different. But only one offered her independence.

At 18 she moved to Chicago, where she became a prostitute. Working under the name Josephine Airey, she accumulated considerable savings. But she was restless. In the mid-1860s, clients flush with cash from a gold rush in Montana began reporting a serious shortage of "professional women" in that territory. Sensing an opportunity, the 22-year-old made the 2,300km trek west.

According to Lael Morgan's book Wanton Women: Madams, Money, Murder and the Wild Women of the Montana Frontier, about 1,000 male miners were encamped at a place called Last Chance Gulch when Airey arrived. Also, about 40 mostly Chinese and African-American sex workers were plying their trade there.

Hurdy-gurdy house

Airey purchased a log cabin for $375, hired girls and musicians and opened what was known euphemistically as a hurdy-gurdy house. The miners’ wages were high, their hours were long and the mining season was short. So Airey’s business model was simple: to extract as much money as she possibly could from these men in the short time they were on her premises.

Customers were charged a dollar for a dance with her girls, and then were pressured to purchase vastly overpriced drinks. Further arrangements were worked out in back rooms. The businesses boomed. In her first five years, prostitution accounted for 44 per cent of all real estate transfers in what had since been renamed the city of Helena. “Chicago Joe” (as she was known) gained a reputation as a shrewd businesswoman and a fair employer.

In October 1871 several of her rivals’ businesses were destroyed in a fire. A week later the great Chicago fire burned out the companies who insured them. Airey’s properties were unaffected and she expanded aggressively. In 1875 Helena became the capital of Montana territory. Airey’s customer base now included lawyers and legislators who, unlike miners, worked all year round. She became a prominent local philanthropist and society hostess.

By the silver boom of the mid-1880s, Helena was thriving. A town of less than 10,000 people, it was home to more than 50 millionaires.

Respectability

In 1886 Airey was charged with running an illegal hurdy-gurdy house. Morgan’s book dryly notes that “it was difficult to find five men [in Helena] who could claim to be impartial” on the question of her guilt.

She hired one of the territory’s sharpest lawyers and was acquitted on a technicality: her establishments employed live orchestras rather than crank-turned hurdy-gurdy players. At the next election, she threw her resources against the district attorney who had prosecuted her and helped secure his defeat. But times had changed. Helena was becoming respectable.

Airey’s greatest triumph came in 1889 when she opened the $30,000 Coliseum variety theatre. Despite opposition from religious conservative groups, its lavish boxes, comfortable seats, top acts (and discreet alcohol service) made it a surprise family favourite.

Unfortunately she lost most of her properties in the economic panic of 1893. She kept the Coliseum but, no longer able to afford the top acts, audiences tapered off. She died of pneumonia in 1899, aged 55. Despite her diminished circumstances, her death received "huge and uncritical" front page news in the Daily Independent.

Airey's funeral procession from the Cathedral of the Sacred Heart to the Catholic cemetery had all the trappings of a state funeral. Asked to explain his presence at the funeral of a brothel owner, the former (and future) Montana governor Joseph Toole stated that "Chicago Joe" had helped him, and many others, in their times of need.