History has a funny way of scrubbing out the boring parts to make room for the legends. When you think of William Henry McCarty—the boy the world eventually called Billy the Kid—you probably picture a dusty gunfighter squinting into the New Mexico sun. You don't usually think of a scrawny kid in a New York basement or a teenager desperately trying to take care of his dying mother. But the billy the kid family tree is actually where the real story starts. It’s a messy, tragic, and surprisingly normal Irish immigrant story that ended up producing the most famous outlaw in the West.
The truth is, Billy didn't just sprout from the desert floor with a Winchester in his hand. He had a mom, a brother, and a father who vanished so early he might as well have been a ghost. Honestly, a lot of what people "know" about his family is just guesswork from 19th-century newspapers that loved a good lie. If you want to understand the Kid, you've got to look at the McCartys, not the "Bonneys."
The Mystery of the McCarty Parents
Most historians agree Billy was born in New York City, likely around 1859. His mother was Catherine McCarty, an Irish immigrant who probably fled the Great Famine. She was tough. She had to be. In a 1860 census, we see a Catherine McCarty living in Manhattan with a husband named Patrick and a young son named Henry.
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Patrick McCarty is the "X" in the equation. Some researchers think he died in New York, while others believe he might have been a stepfather or even a relative. Either way, by the time Catherine decided to move West, Patrick was gone. She was a single mother with two boys—Henry (Billy) and his younger brother, Joseph.
You've gotta imagine the guts it took for a woman in the 1860s to pack up two kids and head for the frontier. They didn't have much. Catherine made ends meet by taking in laundry and baking. People who knew her back then said she was a "jolly Irish lady," full of life despite the fact that she was slowly being eaten away by tuberculosis.
The Stepfather: William Antrim
In 1873, Catherine married a man named William Antrim in Santa Fe. This is where the family tree gets another branch and a lot of confusion. Henry and Joseph actually served as witnesses to the wedding.
Antrim wasn't exactly a "father of the year" candidate. He was a prospector, which basically meant he spent all his time in the hills looking for silver and very little time at home. When Catherine finally died of "consumption" in 1874, Antrim did something pretty cold: he placed the boys in separate foster homes and basically washed his hands of them.
The Forgotten Brother: Joseph McCarty Antrim
While everyone knows Billy, almost nobody talks about his brother, Joseph. If you're looking at the billy the kid family tree, Joe is the one who actually survived to see the 20th century. He was younger, likely born around 1863.
After their mother died and their stepfather bailed, Joe and Henry's paths split. While Henry was out getting into "The Lincoln County War" and becoming a legend, Joe was drifting. He became a professional gambler. He spent time in Silver City, Trinidad, and eventually Denver.
Joe lived until 1930. Can you imagine that? He saw the Wild West turn into the era of jazz and automobiles. Reporters would occasionally track him down to ask about his famous brother, but Joe was usually pretty tight-lipped. He died in poverty in Denver, a quiet end for the brother of the most famous "social bandit" in American history.
Was there a sister?
There’s a 1860 census record that mentions a seven-year-old girl named Bridget in the McCarty household. If she was Billy’s sister, she disappeared from the record early on. Some think she died young; others think she stayed in the East when Catherine moved. It's one of those gaps in the tree that historians still argue about over whiskey.
Why the Bonney Name is a Fake
If you’re digging through the billy the kid family tree looking for "Bonney," you’re going to hit a brick wall. The name William H. Bonney was a total alias. He started using it around 1877, likely to distance himself from his past or his family while he was on the run.
He wasn't a Bonney by blood. He was a McCarty through and through. Even the name "Henry Antrim"—which he used for a while—was just his stepfather’s last name. The Kid was a man of many identities, but his DNA belonged to that Irish family from the New York slums.
Are there living descendants?
This is the big question. Did Billy the Kid leave any kids behind? Officially, no. He died at 21, and he wasn't married. However, New Mexico is full of stories about his "secret" children.
The most famous rumor involves Paulita Maxwell, the daughter of a wealthy rancher in Fort Sumner. People at the time swore she was pregnant with Billy’s child when he was killed by Pat Garrett. Paulita always denied it in her later years, but she did admit she had a crush on him.
There are also several families in the Southwest who claim descent through "Brushy Bill" Roberts or John Miller—men who claimed to be Billy the Kid having survived the shootout in 1881. If you believe the official history, the lineage ended with Billy in a darkened room in Fort Sumner. If you believe the legends, the McCarty bloodline might still be walking around New Mexico today.
Looking for the Truth in the Paper Trail
If you want to trace this yourself, the best places to look aren't the history books, but the raw records.
- The 1860 New York Census: Look for Patrick and Catherine McCarty in the First Ward.
- The 1870 Kansas Census: You'll find Catherine and the boys in Wichita.
- Silver City Records: Check the local papers from 1874 for Catherine’s obituary. It’s heartbreakingly brief.
The reality of the billy the kid family tree is that it was a family broken by the harshness of the era. Tuberculosis, poverty, and a disappearing father figure created the environment that pushed Henry McCarty to become Billy the Kid. He wasn't born a killer; he was an orphan trying to survive in a world that didn't have much room for scrawny Irish kids.
To truly understand the Kid, stop looking at the gunfights. Look at the laundry Catherine scrubbed in Wichita. Look at the brother who died in a Denver boarding house. That’s where the real history is buried.
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If you're interested in digging deeper into the genealogy, your next step should be checking the digitized records of the New Mexico State Archives. They hold the original marriage license for Catherine and William Antrim, which is one of the few documents that proves the family actually existed as a unit before the legend took over.