American Civil War enthusiasts mustered at a Brighton cemetery to unveil a memorial to a forgotten hero snubbed by his former regiment.

Forty Union and Confederate troops in period uniform stood to attention as the Union flag was pulled away to reveal a new headstone marking the grave of Lieutenant Colonel Arthur Fremantle.

Fremantle, who lived on Brighton seafront, died in 1901 aged 65 after a distinguished career in the British Army.

During the Civil War, he obtained six months' leave from his regiment, the Coldstream Guards, to travel in America.

He kept a diary of his experiences, which included a vivid description of the Battle of Gettysburg, regarded by many historians as the defining moment of the conflict.

Today, Lt Col Fremantle is regarded as a hero in the US but he has been forgotten by most people in Britain, including his regiment, which declined to send a representative to the unveiling of the memorial at Woodvale Cemetery, off Lewes Road.

Neville Wantling, who spearheaded the campaign for the £2,500 gravestone, said: "They didn't even send a letter, which was very disappointing."

The chapel was packed for a service which was attended by several members of the Fremantle family, including Lord Fremantle, Lord Lieutenant of Buckinghamshire, and Commander Charles Fremantle, a serving Royal Navy officer.

They sang the hymn Jerusalem before parading outside during a break in the torrential rain to fire three volleys above the grave with their muskets.

A wreath of blue and grey flowers, reflecting the colours of the Union and the Confederacy, were laid at the base of the grave, which bore the inscription: "Forgotten hero remembered".

Roger Hughes, who portrays Lt Col Fremantle at battle re-enactments, flew in from the States, where he lives, for the ceremony.

The memorial, which replaced one removed in 1935 for safety reasons, was paid for by a group of historians called the General Staff of the Blue and Grey.

A spokesman for the Coldstream Guards said the regiment was serving in Northern Ireland and could not spare anybody to attend.