Chinese Americans have a long and varied military history dating back 200 years on US battlefields, working alongside Americans, fearlessly running into the fray as muskets and cannons fired, and some losing their lives.

While the efforts of those who served in World War II are widely known, the stories of the estimated 74 Chinese men who served in the US Civil War tend to have been forgotten.

Writer Ruthanne Lum McCunn from San Francisco, California, has done extensive work for decades to uncover intricate details about the lives of these Chinese Americans.

McCunn of Chinese and Scottish descent told China Daily that the reason that this part of history isn't very widely known is that "American history unfortunately continues to lack diversity or nuance".

The Civil War erupted over a dispute over whether slavery should be permitted to expand into the western territories or stopped from this expansion, which the North feared would lead to the abolition of the heinous trade especially after the election of anti-slavery president Abraham Lincoln.

As the Union (North) fought the Confederacy (South) between 1861 and 1865, around 31 Chinese soldiers fought for the Union Army, 43 were in the US Navy and around five are known to have sympathized with the Confederates, according to McCunn.

Her article Chinese in the Civil War: Ten Who Served, written nearly 30 years ago, provided an update to a widely missed part of this history. She has also written numerous books, including Chinese Yankee: A True Story from the Civil War.

In 1860, the US Census recognized just three races: white, black and mulatto. There was often confusion over how to classify Asian soldiers. It wasn't until 1910 that the census broadened its racial classifications.

Corporal Joseph Pierce of the 14th Connecticut Volunteer Regiment fought and was wounded at Antietam and Gettysburg during Pickett's Charge, ordered by Confederate General Robert E Lee, in an all-white and male unit. He was likely the only Chinese man out of 160,000 men at Gettysburg, John Dynia, a retired US Army colonel and Civil War enthusiast, found. Dynia campaigned to get Pierce's image on the Gettysburg Wall of Faces at the Visitor Center in Gettysburg National Military Park.