James Madison, the fourth president of the United States, was in office and Congress was authorizing the use of steamboats to transport mail when the Great Mesquite Tree was taking root.
It is still standing and budding out now with a few spring leaves - not yet ready to give up the ghost.
The ancient tree, with an estimated age of about 200 years, is a massive, well-weathered and much-revered presence at Roy P. Drachman-Agua Caliente Park east of Tucson.
Its fans feel joy - and a bit of relief - when it shows fresh signs of life.
"It's a great, historic part of the park, and I'm thinking how beautiful it looks every year when it greens up," said Amy Lough-ner, manager of the park.
"The tree has a lot of character. Visitors really appreciate it," Loughner said. "I would hope it will be around for a while."
EXACT AGE IS UNKNOWN
A sign at the park says the velvet mesquite "is estimated to be over 200 years old."
"Tree-ring dating of mesquites is not possible because of their desert adaptive physiology," the sign says.
George Montgomery, curator of botany at the Arizona-Sonora Desert Museum, explained that tree-ring dating isn't dependable because mesquites are "opportunistic growers" that grow with rainfall patterns. That means they might grow in diameter during summer and winter rains, confusing the dating process.
An estimate for their longevity would be in the range of 150 to 200 years, Montgomery said.
Pete Filiatrault grew up in the shadow of the Great Mesquite.
"My family owned and operated the Agua Caliente Ranch as a working cattle ranch from 1951 until 1959" - long before the site became a Pima County park in 1985, said Filiatrault, 74. "I was 12 when we arrived there and 20 when we left."
The hot spring that gave the park its name was flowing abundantly in the 1950s, he said.
The tree sat then, as it does today, in a courtyard next to the ranch house where Filiatrault grew up.
"I was right next to that tree and saw it every day," he said. "It was very large, equal in size to what it is now, but it was much fuller in the 1950s. It had more branches, more growth in the interior."
Filiatrault, a co-founder of the Friends of Agua Caliente Park, recalls youthful days of climbing up in the mesquite and perching on a branch.
"At one time there was a rock bench under it where you could sit," he said.
He said rock supports under the tree's trunk were in place before his family moved to the ranch in the 1950s.
The mesquite, which is listed as one of the "Great Trees of the Old Pueblo," might already be one of the oldest of its kind - but Filiatrault and others wish it more years to come.
"I don't know if there's an older mesquite tree in Arizona. I don't know of an older one," Filiatrault said. "I hope to see it go on. I would hope it would live as long as I do, or longer. It's a beautiful tree."
did you know?
Tucson is home to some other large and quite old mesquite trees - including one in a courtyard near the Tucson Museum of Art downtown.
Contact reporter Doug Kreutz at firstname.lastname@example.org or at 573-4192. On Twitter: @DouglasKreutz