(written from a Production point of view)
William Oliver "Billy" Campbell (born 7 July 1959; age 60) is the actor who portrayed Thadiun Okona in the Star Trek: The Next Generation second season episode "The Outrageous Okona". He is sometimes credited as Bill Campbell or Billy Campbell. He was the second choice for the role of William T. Riker on TNG, but Jonathan Frakes won the part.
Campbell is now best known for his role as Jordan Collier in Ira Steven Behr's hit show The 4400.
Campbell also portrayed the Rocketeer in the film of the same name, which co-starred Paul Sorvino, Terry O'Quinn, Tiny Ron, Ed Lauter, Max Grodénchik, and Clint Howard. He also appeared in the films Bram Stoker's Dracula (with Winona Ryder) and Enough. From 1999 to 2002, he played divorced father Rick Sammler on the ABC television drama series Once and Again, which co-starred Susanna Thompson (who played his ex-wife Karen) and Jeffrey Nordling. He also appeared with Kevin Conway, Joseph Fuqua, W. Morgan Sheppard and Andrew Prine in the Civil War films Gettysburg and Gods and Generals (though in different roles – and on different sides – as a young Union officer in the former and General George Pickett in the latter); in 2013 he played Abraham Lincoln in Killing Lincoln, a National Geographic docudrama about his assassination. Lately, he's appeared in Law & Order: Special Victims Unit and Frasier (with Kelsey Grammer). He recently appeared in a two-parter of Shark, opposite Star Trek: Voyager star Jeri Ryan. In 2001, he played the Biblical prophet Moses in In the Beginning; in the same film were also Star Trek actors Steven Berkoff and David Warner. From 2014 to 2015, he portrayed Dr. Alan Farragut in the SyFy series Helix opposite Jeri Ryan and Steven Weber.