It�s often said that if you want a friend in Washington, get a dog.

At the end of his life, Sully the service dog was President George H.W. Bush�s. The yellow Labrador Retriever visited the president�s remains in the Capitol rotunda Tuesday alongside other people in wheelchairs that benefited from the Americans With Disabilities Act that Bush signed in 1990.

John Miller, the president and CEO of America�s VetDogs, said the Bush family contacted Walter Reed National Military Medical Center after the late president�s wife of 73 years, Barbara, died in April. America�s VetDogs chose Sully in part for his calm temperament.

�After Mrs. Bush�s death, general companionship was a big part of Sully�s job,� Miller said in a phone interview. �One of the things that I think was important to the president was the rest command, where Sully would rest his head on the president�s lap.�

Sully is 2 years old. He was named for retired airline pilot Chesley �Sully� Sullenberger III, who became famous for landing a damaged passenger jet on the Hudson River in 2009, saving everyone aboard.

WATCH: Sully, George H.W. Bush�s service dog, made a final visit with the former president today, joining others paying respect to Bush as he lies in state in the Capitol Rotundapic.twitter.com/gFAWZ6tiCa

— Breaking911 (@breaking9111) December 4, 2018

Sully the dog achieved worldwide fame after a Bush family spokesman tweeted a photo of Sully laying by Bush�s flag-draped casket with the caption: �Mission completed.�

The pup traveled to Washington with the funeral retinue. And on Tuesday morning, officials issued a two-minute warning for Sully�s arrival in the Rotunda. Sully padded in, his leash held by Valerie Cramer, America�s VetDogs service dog program manager.

At her command, he lay down � and threw a glance over his shoulder at the photographers scrambling to get his photo. He didn�t seem fazed. Cramer then led him around the casket to sit among the others. After a few minutes, the procession headed out.

Sully is headed back to America�s VetDogs in Smithtown, New York, where he was born and trained, Miller said. Then he�ll go for training at Walter Reed to help brace, retrieve and otherwise help the veterans getting care there. Sully will be working with two dogs already in service at the veterans hospital, Sgt. Dillon and Sgt. Truman.

The dogs provided by America�s VetDogs are provided free of charge for a service that can cost upward of $50,000 to breed, train and place them, Miller said.

(AP)