We know that ancient Egyptians venerated cats—both as pets and as near-diety—and when beloved pet cats died, they were mummified to be buried with their owners when it was their turn to shuffle off the mortal coil.

But in the U.S., honoring our cherished domestic companions with their own formal burial sites took about 120 years after we became a nation to take hold.

Memorials to Our Pets

The oldest operating pet cemetery in the world is in the U.S.: Hartsdale Pet Cemetery was almost accidentally founded, in 1896, by a kind-hearted New York City veterinarian who was trying to help a woman who was distraught at the death of her dog and had called his offices looking for suggestions as to how to honor her pet—instead of “dispose” of him. Dr. Samuel Johnson offered a bucolic burial spot in an apple orchard on the property of his country estate in Westchester County.

Word got out—especially after a newspaper reporter to whom Dr. Johnson had casually told the tale published an article on the subject—and Dr. Johnson was flooded with requests, so he set aside three acres of his apple orchard for pet interments. After just a few years, hundreds of animal companions had found their final resting place here, with grave markers, little fences, statuary, and, in one case, a spaniel named Major was put to rest in a glass-topped satin-lined casket, while “mourners sang an expressive doxology,” as the cemetery’s written history notes.

A Lion Laid to Rest

In 1913, Hartsdale Pet Cemetery officially incorporated as a business—and in the next three years welcomed and buried more animals than it had in the entire 18 years before, including a lion cub that a princess living in the Plaza Hotel had rescued from a circus. Today, the cemetery is 5 acres, has been recognized by and listed on the National Register of Historic Places, and is home to more than 100,000 loved ones—including more than a few remains of the pets’ owners, who wanted to be interred side by side with their well-loved companions.

Another famous U.S. pet cemetery—and also, maybe just a little infamous—is on the opposite coast, tucked away in Napa Valley. Founded in 1971, Bubbling Well Pet Memorial Park is quite a few decades younger than Hartsdale Pet Cemetery, but it was brought to national attention when it appeared in a film, Gates of Heaven, the first documentary made by the now-famous filmmaker Errol Morris (The Thin Blue Line, the AcademyAward-winning Fog of War).

Bubbling Well was founded by Cal Harberts, who was looking for a good business prospect when he dreamed up Bubbling Well, according to his son, Dan Harberts, who is now the owner and operator of the cemetery. In Gates of Heaven, Dan, then a recent escapee from the bounds of college, comes across as a dutiful, if perhaps bored, employee, but as time went on, he came to understand the real importance of what pet cemeteries were offering their clients. “What we do here, I think, is very important, and I see myself doing this probably for the rest of my life,” he said in a recent interview with CBS News. "I don't know if I'm ever going to retire.” (The Hartsdale Pet Cemetery is also owned and run by a family, and is being passed down through generations.)

The CBS interviewer noted: "People bury people because they have to, but they tend to bury pets because they want to."

Finding the Perfect Resting Place

Bubbling Well is divided into different sections for different needs and kinds of pets: there’s “Kitty Kurve” (for cats, one assumes), “Gentle Giants” (for large breeds”, “Champions,” “Mighty Midgets,” as well as the “St. Francis Garden,” which is a location in the park where owners can scatter the ashes of their companion if they choose. There is also the Foothill Gardens section, where 300 pets who were relocated from the former Foothill Cemetery. (The move of the previously buried animals is the news item that caught Errol Morris’s eye and prompted him to pursue his documentary.) All told, more than 12,000 pets have found their permanent resting place here.

There are now more than 700 pet cemeteries in the U.S., according to the International Association of Pet Cemeteries (and yes, pet cemeteries exist all around the world). Regardless of their fame or history, they are all welcoming and comforting sites, where a visitor can see the range of expressions of love we have collectively for our furry friends. As one of the subjects in Gates of Heaven put it: "Surely at the gates of heaven an all-compassionate God is not going to say, well, you're walking in on two legs—you can go in. You're walking in on four legs—we can't take you."

Roger Ebert called Gates of Heaven one of his top-ten films of all time, because of its deadpan look at many of the quirks of humanity that are expressed by the film’s subjects. But at the end of the film, he wrote in his review, “having laughed earlier, we find ourselves silent. These animal lovers are expressing the deepest of human needs, for love and companionship.”

And building memorials to that clearly makes sense.