His first book and national exhibition, The Triumphant Spirit: Portraits & Stories of Holocaust Survivors, was featured on the CBS Sunday Morning show and on CNN. This book received accolades from the American Library Association; was praised in the Congressional Record; was selected as First Place Winner in Writer's Digest Magazine; was named "Best Coffee Table Book of the Year" by a Denver newspaper and received the Gold Medal from the Colorado Independent Press Association.

One critic said his work is "unsurpassed in its poignancy and drama. The strength of the photos alone is a major achievement, seeming to have no end of ideas for adding thoughtful impact to these compositions. His subtle use of light and shadow enhances the mood and adds drama to the portraits."

Two photographic legends--Richard Avedon and Arnold Newman--also singled out his work, which has been prominently featured in major daily newspapers and in numerous local and regional telecasts and in national and international photographic publications. In 1998, his work was selected as " the very best of the best" for display at the world's largest photo show, Photokina in Cologne, Germany. Nick has received numerous national awards.

Continuing with the military theme established with the Medal of Honor project, Del Calzo’s latest book pays homage to America’s aerial combat pilots. He was the executive producer and lead photographer for the book, Wings of Valor: Honoring America’s Fighter Aces. This book was published by the Naval Institute Press in November 2016.

Another Del Calzo project, In Honored Glory, is an exclusive collection of iconic images that honor America’s spirit of freedom. This series includes black and white photographs with quotations that pay homage to our nation’s fallen heroes. Other images equally inspire patriotism and pay tribute to active service members and to all veterans who served our nation with honor and distinction. The project’s theme is: All who served deserve to be remembered. This project was first introduced during a presentation at the opening session of the 2011 American Legion’s National Convention.

This body of work spawned the creation of a patriotic educational program designed to inspire young Americans. The Saluting America School Program has been embraced by schools throughout Colorado since its introduction in 2012. This program supports and encourages interactions among K-12 students, veterans, and active military through classroom and school-wide activities that educate, inform, and raise awareness of the sacrifices made to maintain America’s freedoms.