Entertaining the troops

Recording artist Kimberly Perry of The Band Perry and Army Spc. Kelly Gregg perform onstage during ACM Presents: An All-Star Salute To The Troops at the MGM Grand Garden Arena on April 7, 2014 in Las Vegas, Nevada.

Singer Kellie Pickler and Staff Sgt. Baily Zimmerman perform onstage during ACM Presents: An All-Star Salute To The Troops at the MGM Grand Garden Arena on April 7, 2014 in Las Vegas, Nevada.

Paris Hilton attends the USO Swinging Salute to our Troops Fleet Week kick off at The Union Square Ballroom in New York on Wednesday, May 26, 2010.

Soccer player David Beckham surprised British troops at Camp Bastion, Afghanistan, on Saturday, May 22, 2010.

California Gov. Arnold Schwarzenegger hugs a U.S. soldier during his visit to Camp Victory on the outskirts of Baghdad on Nov. 16, 2009. Schwarzenegger flew into Iraq on a morale-boosting visit for troops, drawing cheers from servicemen and women.

"The Hangover" star Bradley Cooper, right, and sports personality and model Leeann Tweeden sign autographs for service members at Bagram Air Base, Afghanistan, on July 14, 2009, during a United Service Organizations tour to the U.S. Central Command area of operations. The tour also featured National Football League hall of fame coach Don Shula, all-pro NFL running back Warrick Dunn and actor D.B. Sweeney.

Former Miami Dolphins coach Don Shula addresses the crew of the aircraft carrier USS Ronald Reagan under way in the Atlantic Ocean on July 13, 2009. Shula and other celebrities were visiting the ship as part of the USO Summer Troop Visit to thank service members for their service and to help boost their morale. The ship is deployed to the U.S. 5th Fleet area of operations.

Stephen Colbert of Comedy Central's "The Colbert Report" sports a camouflage suit during his performance for U.S. military personnel at Al Faw Palace in Baghdad on June 7, 2009, in Baghdad, Iraq. Al Faw Palace is located at the U.S. military's Camp Victory near Baghdad's airport.

Former "American Idol" contestant and country musician Kellie Pickler signs autographs after performing for U.S. service members during a stop on the 2008 USO Holiday Tour in Kandahar, Afghanistan, on Dec. 17, 2008. The tour's host, Chairman of the Joint Chiefs of Staff Navy Adm. Mike Mullen, and his wife Deborah joined Kid Rock, comedians John Bowman, Lewis Black and Kathleen Madigan and actress Tichina Arnold and Pickler on the tour to boost the morale during the holiday season.

Jessica Simpson poses with troops on March 10, 2008 in Camp Buehring, Kuwait. Simpson, Pussycat Dolls, Filter, Disturbed, Carlos Mencia, DJ Z-Trip and Metal Sanaz performed at the base for "Operation MySpace," a live concert broadcast on MySpace.

Actor Gary Sinise, right, listens to U.S. Army CW 4 Leif Neely of Woodbridge, Va., tell about how he was wounded while flying his helicopter on a mission over Mosul, Iraq, during a visit by Sinise to the hospital at Forward Operating Base Mazur, Iraq, on May 20, 2007. Sinise was on a USO-sponsored meet-and-greet tour.

Country music star Toby Keith, right, plays with Scotty Emerick during a USO performance at Camp Victory in Baghdad on May 17, 2005. Keith taped a portion of the show to be played during the Academy of Country Music Awards program in Las Vegas later that night.

Wayne Newton performs during the USO's annual gala at the Hilton hotel in Washington on Oct. 14, 2004. The event honored the legendary entertainer for his service to the USO as well as paying tribute to five service heroes from each branch of the armed forces.

Supermodel Rebecca Romijn, right, and model Leeann Tweeden listen to Bubba Sparxxx perform at Baghdad International Airport as the USO Tour visited troops in the Iraqi capital on June, 19, 2003. The soldiers got a break from the heat and the fighting to hear music and get autographs from a number of performers traveling with the show.

Robin Williams takes a picture with a G.I.'s camera as he entertains troops at Baghdad International Airport on Dec. 16, 2003. Williams poked fun at military life and world politics during his routine for hundreds of troops.

Actor Ben Affleck addresses the crew on the flight deck aboard the USS Enterprise in Bahrain on Dec. 22, 2003. Affleck, kicking off a USO-sponsored tour of the Arabian Gulf, was visiting deployed service members throughout the gulf region. Affleck was aboard the carrier previewing his new film at the time, "Paycheck"

Kid Rock performs for U.S. troops at Baghdad International Airport on June 19, 2003.

Actress Alyssa Milano rallies troops aboard the USS Nimitz in the Arabian Gulf on June 19, 2002.

Rock band Aerosmith, (from left to right) Tom Hamilton, Joey Kramer, Joe Perry, and Steven Tyler, pose on the deck of the aircraft carrier, USS Harry S. Truman, pier side October 9, 2002 at Norfolk Naval Station. The band visited with sailors and toured the ship as they returned to perform in the area, having cancelled their original performance scheduled for September 11, 2001.

Legendary entertainer Bob Hope performs for military personnel at the USO Christmas Tour in Saudi Arabia during Operation Desert Shield in 1990. In 1996, Congress honored Hope by declaring him the "first and only honorary veteran of the U.S. armed forces." He appeared in or hosted 199 known USO shows. Hope marked his 100th birthday on May 29, 2003, and died on July 27 that year.

Marilyn Monroe entertains the troops in Korea in 1954. The actress would say more than once in her life that the adulation she felt in Korea by the servicemen -- a group of fans who had helped make her a star -- was the high point of her career. As she performed before thousands of troops in bitter cold temperatures, wearing only a scanty, plum-colored dress, she acknowledged her debt to them as they warmed her with their unconditional adoration.