But his lifelong efforts to remove the stain on his record were unavailing and he was buried in an unmarked grave in Atlanta. The army did not yield until 1976, when his discharge was upgraded to honourable, but his conviction was not overturned. His body was exhumed and moved to his home town of Thomasville in Georgia, where he was buried with military honours. There is talk now of moving him again, this time to Arlington National Cemetery. Mr Clinton has chosen to honour Flipper during Black History Month, when schools across America focus on both the familiar and little-known struggles against discrimination in the nation's past.
Scholars believe it is the first time any presidential pardon has been granted posthumously.
Flipper was born to slave parents in 1856 and learnt to read at the age of eight with the help of a slave who taught school at night in a woodshed. After the Civil War, Flipper attended a number of formal schools culminating in three years at Atlanta University before he was accepted by West Point. Flipper maintained his dignity at West Point by staying aloof and remaining faultlessly polite to everyone around him. Colonel Andre Sayles, the highest-ranking black on the academy faculty, said Flipper remained an inspiration to cadets as one who refused to buckle under pressure.