Arkansas: On the day Gertrude Weaver is said to have been born, the US had just won a major victory in the Spanish-American War, and you could see a matinee show at the Los Angeles Theatre downtown for 25 cents.

On Wednesday, nearly 117 years later, Weaver had her nails painted pink. Although the Arkansas native enjoys her regular manicures, this one was special: At 116, she’s now believed to be the oldest person in the world.

And she believes the key to longevity is treating other people kindly.

“I treat everyone the way I want to be treated,” Weaver told reporters on her 116th birthday when she received a letter from President Barack Obama. She is the world’s oldest person according to the Gerontology Research Group of Los Angeles.

“We did a little bit extra today,” said Mary Bennett, who is married to Weaver’s grandson. “She looks so pretty.”

With the death on Wednesday morning of 117-year-old Misao Okawa of Osaka, Japan, previously named the world’s oldest living person, the title is expected to move now to Weaver and back to US soil, where it will likely remain for a while. (The second- and third-oldest people in the world, both women, are Jeralean Talley, 115, of Michigan and Susannah Mushatt Jones, also 115, of New York.)

The daughter of Arkansas sharecroppers, Weaver moved to Los Angeles in the 1950s and lived in California for years before returning to Arkansas in the 1970s, Bennett said. Today, she lives in a retirement home in Camden, Ark.

“She is just a sweet person, and she always says she has three keys to life: loving God, working hard, and loving everybody and treating everyone the same,” Bennett said.

Up until last year, she enjoyed “wheelchair dances” at the senior home and still today is known to “call the Hogs” _ a University of Arkansas tradition the nursing home staff taught her which involves yelling “woo, pig sooie!” and raising her arms.

Robert D. Young, who tracks supercentenarians, or people over the age of 110, for the Los Angeles-based Gerentology Research Group, said he met Weaver last year when he flew to Arkansas to celebrate her birthday and present her with a plaque that recognised her as the oldest living American. She was, he says, “very sweet.”

“Not everybody is sugar and spice and everything nice at that age,” Young said. “A year ago, she was still strong. I was definitely impressed.”

After retiring, she lived with her granddaughter and moved to Silver Oaks Health & Rehabilitation Centre in 2009 when her granddaughter had health problems, the facility’s administrator Kathy Langley said.

“She’s an absolutely amazing lady,” Langley said.

Weaver’s 93-year-old son visits on a regular basis.

“She said she has been blessed with a long and healthy life because of the way she has treated others,” Langley said.

Although she has become weaker since July, Bennett says, every Sunday Weaver attends church services at the home with her 93-year-old son, Joe Weaver, and spends time talking with her family. Joe, the last surviving of her four children, turns 94 on Tuesday.

Official records say Weaver was born July 4, 1898, but no one knows for sure exactly how old she is, Young says.

Birth records didn’t exist in Arkansas when Weaver was born, he says, and census records from 1900 say Weaver was born April 1898. But official Social Security records put her birth date at July 4, 1898. Young says at that time, it was common for the Social Security agency to assign a person a birth date if they couldn’t provide a birth certificate — January 1, July 4 and December 25 were popular choices.

A marriage certificate from 1915 stated only Weaver’s age — 17 years old for a June wedding, a stronger case for an April birthday.

“Even then, is it April 1 or April 30? This information is lost in the sand of time,” Young says.

Either way, as long as Weaver’s title as oldest living person isn’t contested, she’s still more than a year older than the next-oldest person. She’s also, according to the GRG database, the seventh-oldest person ever to have lived; the oldest person ever was Jeanne Calment, a French woman who died at the age of 122 years, 164 days.

It may take awhile before the Guinness World Book of Records, which previously recognised Okawa as the world’s oldest living person, to name Weaver her successor. Sometimes the publication takes extra time in case others around the globe want to challenge the standing.

In an email, Guinness World Records said it was “saddened” to learn of Okawa’s passing, and is “currently investigating potential successors” for title of oldest person living.

For now, though, Bennett says her grandmother has enjoyed dozens of visits from family members, the media, and even political officials.