Their second son, Joseph Parkin, was born in 1839; a third son, John, was born on 7 January 1842. In 1842 Mayall decided to travel to North America. It was there in Philadelphia, Pennsylvania he became known as John Jabez Edwin Mayall. According to Canon Hulbert of Almondbury in Yorkshire, the 28-year-old was an intelligent young man who had ambitions beyond the linen trade: "Slaithwaite was scarcely a sufficient sphere for his genius and he emigrated to the United States, where he took up the then infant Art of Photography; which he much improved by his experiments and discoveries." In an interview with the editor of the Photographic News, Mayall stated that his "first handling a Daguerreotype was on 6 January 1840", two years before he embarked for America. From 1843, Mayall produced a large number of daguerreotypes, including a set of ten pictures illustrating the Lord's Prayer. In 1844, Mayall entered into partnership with Samuel Van Loan, who had previously worked as a daguerreotypist in the English town of Manchester, only 30 miles from where Mayall was living in 1841. Richard Beard had established a daguerreotype portrait gallery at Ducie Place, Manchester on 18 November 1841. Beard had passed on the Manchester studio to the American daguerreotypist John Johnson in November 1842 and it is possible that Van Loan travelled with Johnson when he returned to America in 1844. Mayall and Van Loan established a studio at 140 Chestnut Street, Philadelphia. They were known for the high quality of their daguerreotypes. In October 1844, the partnership of Van Loan & Mayall received a silver medal for work exhibited at the Franklin Institute. At the 1845 Exhibition at the Franklin Institute, daguerreotypes by Van Loan & Mayall were judged "superior and entitled to Third Premium." In 1846 the partnership between Van Loan and Mayall came to an end. John Mayall then established his own Daguerreotype studio at Fifth and Chestnut Street. During his time in America Mayall gave lectures on the art of photography. In May 1846, he delivered a "Memoir on the Daguerreotype" to the Philosophical Society of the United States, which was meeting in Philadelphia. Mayall also had links with Philadelphia's Central High School, where his mentor, Professor Martin Boye held the Chair of Chemistry.