More than a century after she crossed the Rio Grande from Mexico into the US, Eulalia Garcia has become an American citizen at the age of 101.
"I feel really good about what I have accomplished - at my age and with my health," she said.
Ms Garcia, who entered the US on 12 October 1909, became a citizen on the 101st anniversary of her arrival.
She said the first thing she wanted to do as an American was vote in the mid-term elections on 2 November.
"Sure, I do - for the best [candidate]," Ms Garcia said.
The naturalisation ceremony took place on Tuesday in a federal courthouse in Brownsville in the US state of Texas, where Ms Garcia has lived almost all her life.
She now joins an elite list of only 15 immigrants over 100 years of age who have been naturalised as citizens, according to the US Bureau of Citizenship and Immigration Services.
Born in the Mexican city of Monterrey, she has outlived two husbands, her two sons and an endless set of rules and US immigration laws.
She came to Texas in the arms of her mother, Ilaria Mendoza, when she was only six months old.
At that time, it was normal for both Mexicans and Americans to travel across the border in either direction without being forced to show documentation.
Ms Garcia's single mother made a living washing clothes - and together they lived a quiet life in Brownsville.
In 1940, the US Congress passed the Alien Registration Act, or Smith Act, which required all non-citizens already in the country to register with the government.
She registered, along with millions of other immigrants, and received a Certificate of Lawful Entry card, issued to her on 4 April 1941.
With the government-issued card in hand, she crossed the border to visit family and friends for decades without a problem.
The card has now also made it possible for Ms Garcia to become a US citizen.
The US Bureau of Citizenship and Immigration Services (USCIS) commended her efforts.
"Just the fact that at the age of 101, this lady has wanted to become a citizen is an honour for us," USCIS spokesperson Marilu Cabrera said.
'Love for life'
The centenarian's niece, Yolanda Ovalle, who helped her aunt through the application process and in her preparations for the citizenship exam, praised the 101-year-old for her strong will and admirable character.
"This is a very important day for all of us because she deserved to become a citizen. She has always been such a good person," Ms Ovalle said.
"She answered every question, that's why she passed," she added, referring to the US Civics tests given by immigration officials.
"I have never seen someone with her age that doesn't give up on life. She wants to keep on living. She loves her life and is the type of person that never has any problems with anybody."