The Park Inn was situated at 39 Spaw Lane (now Spa Road) in an area close to what is now Queens Park.
Queens Park itself was only opened in 1866 when it was known as Bolton Park. It was renamed in honour of Queen Victoria’s Diamond Jubilee in 1897. The land was previously known as Spaw Fields.
The Park Inn dated back to the early-1850s and was run for the whole of its existence by Thomas and Ann Rothwell. There is no mention of the pub on the 1851 census, but it does appear on the 1853 Bolton Directory.
In 1869, the Bolton Evening News reported that Thomas Rothwell had been suffering from dropsy – or edema, as it is often referred to these days - for the previous three or four years. Dropsy is an abnormal accumulation of fluid in the interstitium, located beneath the skin and in the cavities of the body and treatment in the nineteenth century involved draining the fluid from the afflicted areas.  In an article entitled Extraordinary Medical Case, the paper reported that Mr Rothwell had recently been treated.
“On Monday last the operation of tapping was performed for the fifty-first time. He has had 674 quarts or 1685lbs of water taken from him and yet, strange to say, is yet able to go about the house, and is in remarkably good spirits.” 
Six hundred and seventy-four quarts is the equivalent of over 1300 gallons; 1685lbs is three-quarters of a ton.
Perhaps that’s why the pub as nicknamed Happy As A King.
Sadly, Thomas Rothwell’s good fortune was unable to continue and he died the following year, in 1870. Ann Rothwell continued with the pub and her niece, Elizabeth Frey, was living with her on the 1871 census. The Park had closed by the mid-1870s.
 Wikipedia. Retrieved 11 August 2015.
 Bolton Evening News, 24 July 1869.