I'm going to cheat here. The best summary of Tracy's life I've found can be read here. There is also a comprehensive bibliography of Tracy's work compiled by John D. Squires. I recommend both resources to anyone who wants to find out more about Tracy, which means I can concentrate on the one thing that has been bugging me. I was checking his dates of birth and death and I couldn't find a trace of his birth.
John Squires, the compiler of the lengthy article on Louis Tracy cited above, summarizes the full extent of what is known about the first twenty years of Tracy's life in one fairly short paragraph:
Louis Tracy was born into a comfortable upper middle class family in Liverpool, England on March 18, 1863. His parents had the resources to give him a private education, first at his home in Yorkshire, and then for three years at the French Seminary at Douai. Growing up in relative leisure he amused himself with "sport, volunteering, fishing, and riding," but also joined the 1st Volunteer Battalion of the Yorkshire Regiment. He showed an affinity for the army and by his eighteenth birthday had earned a full certificate for a captaincy, an unusual accomplishment at the time.The date and place of his birth are both noted in his entry in Who's Who. Tracy seems never to have mentioned anything about his family or his parents, and briefly listed his education as "privately in Yorkshire and in France". His journalistic career began in 1884 when he joined The Northern Echo in Darlington, but the first 21 years are a blank canvas.
A small amount of digging turns up Louis Joseph Tracy in the 1901 census, born in Liverpool aged 38 and at that time a boarder at 26 Maida Hill West, Paddington, London, along with his wife Ethel Jane Tracy and son Louis Turgis Tracy. Louis Turgis Tracy was born in Brighton, Sussex, in 1Q 1895. Who's Who notes that Tracy was married and had one son. However, there's a small twist to the story already as Louis Tracy did not marry Ethel Jane Morse, the daughter of John Morse, until 19 October 1896. At 33, Louis Tracy was already a widower.
Their marriage certificate offers the first clue about Louis Tracy's family as it lists his father's name and occupation, Thomas Tracy, police officer.
It took some digging but I've tracked down Thomas through various census returns.
Thomas was born in Ireland, although his age varies from one return to another—he ages 25 years in two decades—so it is difficult to pin down even a rough year of birth. Some time between 1832 and 1838. His wife, Bridget, was also born in Ireland, some time between 1835 and 1842.
Only the 1881 census shows a child's name, Joseph. Note that the 1901 census listed Louis Tracy as Louis Joseph Tracy. Given that there is no sign of a Louis Tracy born in Liverpool in 1863, I started to wonder if Louis Tracy was actually born Joseph Tracy.
Working backwards (and I almost missed it due to poor OCR), I finally found the family in the 1871 census, which helpfully gives some full names: Thomas was married to Bridget Ann Tracy and their son was, in full, Patrick Joseph Tracy. I believe the deaths of both parents are registered in Whitby in 2Q 1907: Thomas in aged 74 (thus born c.1833) and Bridget Anne Tracy aged 72 (thus born c.1835). It would appear they died together as they are registered on the same page of the same volume.
My contention then is that Louis Tracy was born Patrick Joseph Tracy. I've no reason to think that the date of birth 18 March 1863 is wrong, but it seems probable that he was born in Ireland rather than Liverpool. It also seems likely that he was first married in 4Q 1888 in Whitby; there are two possibles: Emma Elizabeth Weston or Jane Ward. A George Collinson was also married in Whitby in the same record and a look in the 1891 census reveals there is a Geo. Collinson married to a Jane living in Hawsker cum Stainsacre, Yorkshire with two sons, one a 2-year-old, which just about fits the timeline for someone married in 1888.
Emma Elizabeth Weston is the likely name of Louis Tracy's first wife. And the death of an Emma Elizabeth Tracey (sic) is registered in Westminster in 2Q 1896, aged 30.
Some of this is a little speculative but it fits together quite neatly. Patrick Joseph Tracy is missing from the 1891 census when Louis Tracy is known to have been in Allahabad, India. The fact that Thomas and Bridget Anne Tracy lived in Whitby where Louis Tracy also lived is another pointer in the same direction. Now all we need is someone with some cash to buy up a few birth, marriage and death certificates to see if they can provide any more clues.