Until his fifth year of National Guard duty, there is no question about his service.
The Globe says those who served with Mr. Bush regarded him as a top pilot and that he spent more time on active duty than was minimally required for reservists.
In the first four years of of his six-year commitment, he spent the equivalent of 21 months on duty.
In May of 1972, George W. Bush moved to Alabama to help in a U.S. Senate campaign and requested permission to serve in a unit in that state.
His superiors, however, later said they did not approve of that unit because it didn't do much.
There were no drills or exercises.
The unit's commander told the Boston Globe that it had no airplanes and essentially met one weeknight per month.
The Globe says that months apparently went by without resolution to Mr. Bush's status and, therefore, no guard duty.
Technically, without new orders, he was still a part of his unit in Texas, but he was living in Alabama.
Mr. Bush was eventually assigned to a unit in Montgomery.
One of the superior officers there told the Globe he could not remember George Bush serving there. But in 2004, he told reporters that he never intended for that statement to mean that Bus hadn't served. He was simply saying he didn't recall his being there..
During that time, Bush failed to take his annual pilot's physical examination and was removed from flight status.
A Bush spokesman told the Globe that Mr. Bush does recall doing some duty in Alabama.
On another occasion, a representative for the president said that Bush made up for any time that was lost by participating in other drills.
But his service records show about a year in which there is no report of duty.
From May to July of 1973, the records show that Mr. Bush did log 36 days of active duty. He was granted an honorable discharge in October of 1973.
The New York Times looked into the allegations in 2002 and concluded that the time Mr. Bush missed had been made up satisfactorily and that his records showed his having performed all the required service.