Maryland joins federal departments and agencies, including the U.S. Postal Service, in closing Wednesday out of respect for the 41st president.
Trump's relations with the Republican establishment have been rocky since his insurgent campaign took him to the party's nomination and then a shock election win in 2016. Bush is survived by five children, including former president George Bush and former Florida governor and presidential candidate Jeb Bush, and 17 grandchildren.
Trump also did not attend the funeral in August of another Republican giant, former senator John McCain.
Bush will be commemorated at a service at the National Cathedral Wednesday morning before being laid to rest Friday in Texas.More news: Tyson Fury, Deontay Wilder fight to split decision
"As much as our family is going to miss this dog, we're comforted to know he'll bring the same joy to his new home, Walter Reed, that he brought to 41", George W. Bush wrote on Instagram. "And President Bush was a bipartisan president".
"President Bush is the first president I ever voted for", said Carrie Hutchman of Mariana, Ohio. Ms. Kasper said the president's steady hand showed through those tumultuous years.
A long list of prominent current and former officials gathered inside the rotunda to pay their respects.
The gesture was marked by decades of friendship between the two politicians, both of whom served in World War II. His final resting place will be alongside Barbara Bush, his wife of 73 years who died in April, and Robin Bush, the daughter they lost to leukemia in 1953 at age 3. Flags on public buildings are flying at half-staff for 30 days out of respect for Bush.
Bush said Trump and Congress' devotion of time to his grandfather's legacy reflects the late president's commitment to bipartisanship.