The following is a press release written by the folks at WikiTree:

In 2016, the WikiTree community created something new: an around-the-clock genealogy research marathon. Since then, there have been many similar events, but the Source-a-Thon remains the original and most popular event of its kind. The 10th annual Source-a-Thon will be held October 3–6, 2025. 

The Source-a-Thon focuses attention on the importance of citing sources. Inexperienced genealogists don’t always record their sources, or their tree has been handed down to them. Second-hand family history deserves to be preserved and shared, but it needs to be verified. In the Source-a-Thon, hundreds of genealogists work side-by-side in teams – such as the Flying Dutchmen, French Fries, Germany Genies, Kiwi Crew, Mighty Maple Leaves, Team Massachusetts, Team Virginia, Toddlin’ Tortoises, and Wizards of Aus – to add sources to as many profiles as possible.

Of a previous Source-a-Thon, high-scoring participant Charlotte Shockey wrote, "Despite little sleep in 72-hours I had a lot of fun working towards a common goal with my fellow WikiTreers in a competitive spirit! The cherries on top were the real sense of community with loads of laughs and friends that were made.”

To encourage participants, individuals and organizations from around the genealogy community are donating prizes to be awarded at random. Over $2,000 in prizes have been donated and more are expected. To donate a prize, please contact eowyn@wikitree.com. To register for the event and be eligible for prize drawings, join WikiTree (it’s free!) and then choose your team.

WikiTree has been growing for 17 years, from the grassroots up. Our community now includes over one million members and over 42 million person profiles. Our tree is considered the most accurate and trusted global tree because of WikiTree’s collaborative culture, sourcing requirements, and incorporation of DNA. See this 90-second animated explanation.