Ann Dermody has been living in the US for the past seven years, having emigrated from Co Carlow to start a new life Stateside with her late American husband.
The 42-year-old said she felt compelled to write a letter not only to express her pride at becoming a US citizen, but also to highlight the "sometimes frustrating and occasionally unfair" US immigration system.
After clicking the submit button on the official White House website, she presumed nothing more would come of it.
A few weeks later, however, she received an email from an official working with the president, inviting her to the Japanese prime minister's state welcoming ceremony. This was followed by a call from the director of correspondence, who contacted her to say her letter had been hand-picked to be passed on to Barack Obama.
"The caller said they select a couple of letters which are given to the president to read," Ann said. "She explained that on occasion he then responds personally to one or two of them.
"She said my letter was one of those selected, and that she has a handwritten note from President Obama she would like to send to me.
"In it he congratulated me on becoming a US citizen - while apologising for not being able to attend the ceremony in person.
"It's the real deal because it's handwritten by him. I was blown away."
However, Ann's contact with the inner workings of the White House didn't end there: "Last Thursday a speech writer called to commend me on the letter and asked if the president could quote it in his weekly address."
Ann said she thought it was "curious" the segments of the letter chosen as part of his weekly state of the nation address.
"The papers we receive…will not change our different accents [OR] skin tones," she wrote. "But for that day, at least, we'll feel like we have arrived."
Speaking to the Irish Independent, she said: "I guess it fits in with the agenda at the moment, because immigration is such a big topic."
While she doesn't want to be the "poster child" for complaining about the US immigration system, she did stress the road to citizenship can be a "long-drawn-out process".
She pointed out that even if you are married to a US citizen, there remains a three-year wait from having legal permanent residency to becoming a citizen.
"A year into that my husband passed away, and then I reverted back to the five-year status, which I thought was a little unfair," said Ann. "I'm very much in support of change for people to have a right to a path to citizenship.
"I did want to remind President Obama that even for the people here legally, it's still not an easy pass. It takes a long time. One of the things that motivated me to write it was to remind him not to forget about those of us who are legal, but still dealing with this broken system.
"There was an emotional factor for me because of my late husband. I know he would have been very proud had he been able to become an Irish citizen. I'm still very proud of my Irish citizenship. If I was forced to forfeit that I don't think I would have done it. I feel honoured to be Irish and American."
Ms Dermody now lives in Alexandria in Virginia, where she's enjoying a highly successful career working as an editor for 'BoatUS' magazine.