The US explorer documented his trek via his Instagram profile (Picture: Colin O'Brady/Instagram).
An American man has become the first person to trek across Antarctica alone without any assistance in an epic 54-day journey that was previously deemed impossible.
Colin O'Brady from Portland, Oregon, finished the 930-mile journey as friends, family and fans tracked the endurance athlete's progress in real-time online.
Mr O'Brady beat British Army Captain Lou Rudd, who himself is attempting to complete a traverse of the continent in honour of his friend, explorer Henry Worsley.
In 2016, former Army officer Henry Worsley died attempting an unassisted solo trip across Antarctica, collapsing from exhaustion towards the end of the trek.
"I did it!", a tearful Mr O'Brady said on a call to his family gathered in Portland for the holidays, according to his wife, Jenna Besaw.
"It was an emotional call," she said. "He seemed overwhelmed by love and gratitude, and he really wanted to say 'Thank you' to all of us."
Mr O'Brady, 33, documented his nearly entirely uphill journey, which he called 'The Impossible First', on his Instagram page.
On Wednesday he wrote that he had covered the last roughly 80 miles in one big, impromptu final push to the finish line that took well over a day.
"While the last 32 hours were some of the most challenging hours of my life, they have quite honestly been some of the best moments I have ever experienced," he said.
Though others have traversed Antarctica, they either had assistance with reinforced supplies or kites that helped propel them forward.
Captain Lou Rudd is also documenting his journey, through a daily blog and SSVC is one of the sponsors of his trek.
Earlier this month, Capt Rudd had to seek medical attention and had started a course of antibiotics and had to take pain relief.
In 2017, the Army captain led an expedition team of reservists who completed a 1,100-mile coast-to-coast crossing of Antarctica in 66 days.
Capt Rudd's spokesman, Martin Brooks, told Forces News: "He'll come down the glacier, there is this point at which the sea ice meets the land ice and then that will be the end.
"This is about the most remote finish line you could possibly imagine."
Ms Besaw said Mr O'Brady planned to stay on Antarctica until Capt Rudd finishes his trek, which is expected in the next few days.
"It's a small club," she joked.
"His intention is to wait for Lou and have kind of a celebratory moment with the only other person on the planet to have accomplished this same thing."
Mr O'Brady described in detail the ups and downs along the way since he began the trek on November 3. He had to haul 170 kilograms of gear largely uphill and over sastrugi - wave-like ridges created by wind.
On day 37, or December 9, Mr O'Brady wrote about how much he had changed, along with a selfie in which he looked almost in pain, snow gathered around his furry hat.
"I'm no longer the same person I was when I left on the journey, can you see it in my face?" he wrote.
"I've suffered, been deathly afraid, cold and alone. I've laughed and danced, cried tears of joy and been awestruck with love and inspiration."