When Susannah Mushatt Jones and Emma Morano were born in 1899, there was not yet a world war or penicillin and electricity was still considered a marvel.
The women are believed to be the last two in the world with birthdates in the 1800s.
They have seen war destroy landmarks and cities and have seen them rebuilt. They witnessed the Gilded Age, a term coined by Mark Twain, and the dawn of civil rights, the rise and fall of the fascists and Benito Mussolini, the first polio vaccines and the first black president of the United States.
Ms Jones, who lives in Brooklyn, New York, tops a list of supercentenarians, or people who have lived past 110, which is maintained by Los Angeles-based Gerontology Research Group, which tracks and maintains a database of the world's longest-living people.
Ms Morano, of Verbania, Italy, is just a few months younger than Ms Jones and is Europe's oldest person, according to the group, which knows of no others born in the 1800s.
Ms Morano has lived on her own since she left her husband in 1938 because he beat her. Now 115, she lives in a neat one-room apartment in Verbania, a mountain town overlooking Lake Major in north-west Italy.
She is cared for by her village: The mayor gave her a TV set, her niece visits twice a day and her adoring doctor of more than 25 years checks up on her regularly.
Ms Morano attributes her longevity to her unusual diet - three raw eggs a day (now two raw eggs and 150 grams of raw steak after a bout of anaemia) - a diet she has been on for decades after a sickly childhood.
"My father brought me to the doctor, and when he saw me he said, 'Such a beautiful girl. If you had come just two days later, I would have not been able to save you'.
Her present doctor, Carlo Bava, is convinced there is a genetic component as well. "From a strictly medical and scientific point of view, she can be considered a phenomenon," he said, noting that Ms Morano takes no medication and has been in stable, good health for years.
Italy is known for its centenarians - many of whom live in Sardinia - and gerontologists at the University of Milan are studying Ms Morano, along with a handful of Italians over 105, to try to find out why they live so long.
"Emma seems to go against everything that could be considered the guidelines for correct nutrition. She has always eaten what she wants, with a diet that is absolutely repetitive," Dr Bava said.
"For years, she has eaten the same thing every day, not much vegetables or fruit. But she's gotten this far."
In Brooklyn , Ms Jones spends her days in her one-bedroom apartment in an OAP housing complex, where she has lived for more than 30 years.
Every morning she wakes up at around 9am, takes a bath and then eats several slices of bacon, scrambled eggs and grits. On a recent day, Ms Jones said little, but family members say she spends her days reflecting on her life and embracing what is left of it - one day at a time. Her living room walls are adorned with family photos and birthday cards made by children in the community.
"Hey, Tee," Ms Jones' niece, Lois Judge, said to her aunt using a family nickname. "How old are you?"
"I don't know," the frail Ms Jones responded.
Ms Jones, who wears a yellow turban on her head and a nightgown most days, watches the world from a small recliner. Posters from past birthday parties, letters from local elected officials and a note from President Barack Obama fill the surfaces.
One of 11 siblings, sh e was born in a small farm town near Montgomery, Alabama. She attended a special school for young black girls and when she graduated from high school in 1922, she worked full time helping family members pick crops. She left after a year to begin working as a nanny, heading north to New Jersey and eventually making her way to New York.
"She adored kids," Ms Judge said of her aunt, though she never had any children of her own and was married for only a few years.
Family members say there is no medical reason for her long life, crediting it to her love of family and generosity to others. Ms Judge said she also believes her aunt's longevity is thanks to growing up on a farm where she ate fresh fruit and vegetables that she picked herself.
After she moved to New York, Ms Jones worked with a group of her fellow high school graduates to start a scholarship fund for young African-American women to go to college. She was also active in her public housing building's tenant patrol until she was 106.
Despite her age, she only sees a doctor once every four months and takes medication for high blood pressure and a multi-vitamin every day, but is blind after glaucoma claimed her eyesight 15 years ago and is also hard of hearing.
She will be 116 next week and family members plan to throw her a party.