Cahill has volunteered at Fortress since 2019 and was named Volunteer of the Year in 2023 after helping Fortress with its move and overseeing a big renovation project in its new building on Terrell Avenue. In late 2024, he accepted a position on the Board of Directors.

Cahill grew up in Dallas where he graduated from Bishop Lynch High School and often visited Fort Worth to see his mother's side of the family. He graduated from Fordham University in The Bronx, New York, where he studied finance and met his wife, Trina. The two moved to Fort Worth in 2013 and have called Fort Worth home ever since. Trina and Cahill own Worthy Outdoors and Hilltop Roofing, in addition to Trina's work as a realtor with Keller Williams. Cahill and Trina have two girls and are members at University Christian Church in Fort Worth where Cahill is on the Deacons Committee.

Cahill spent plenty of time in community service as a student, but his love for service work began as an adult in Fort Worth. Having worked in downtown for some time, he witnessed the dire circumstances that our homeless brothers and sisters live in. He began looking for an effective way to serve in hopes of reversing the odds that are against so many. After sporadically volunteering at a few organizations, Cahill found Fortress by happenstance one day in 2019 when he met a then-board member and immediately knew he had found his service home.

Cahill fell in love with Fortress, its focus on poverty prevention, and its commitment to go beyond providing financial or other tangible resources to those who are searching for a way out of poverty. Cahill and his family consider themselves fortunate to have found Fortress, and are happy to raise their children with Fortress' mission as an example of how we ought to answer God's call to serve others.