Henry McMullin was born on 10 January 1815, in Vinalhaven, Knox, Maine, United States, his father, Archibald McMullin Jr, was 55 and his mother, Sarah Lufkin, was 40. He married Mary Pierce on 21 April 1842, in Vinalhaven, Knox, Maine, United States. They were the parents of at least 5 sons and 2 daughters. In 1850, at the age of 35, his occupation is listed as carpenter in North Haven, Waldo, Maine, United States. He died on 2 May 1886, in Heber City, Wasatch, Utah, United States, at the age of 71, and was buried in Heber City Cemetery, Heber City, Wasatch, Utah, United States.
Henry McMullin constructed two of the first Sawmills in Heber Valley. One was in Center Creek Canyon and was owned by William M. Wall, and James Adams. The other was in Daniels Canyon. He was also a home and barn builder, some of which are still standing. He was the first coffin builder in Heber Valley. He also built the first Hotel in the valley.