This article is awesome: Who Was General Tso And Why Are We Eating His Chicken?:

“General Tso Tsungtang, or as his name is spelled in modern Pinyin, Zuo Zongtang, was born on Nov. 10, 1812, and died on Sept. 5, 1885. He was a frighteningly gifted military leader during the waning of the Qing dynasty, a figure perhaps the Chinese equivalent of the American Civil War commander William Tecumseh Sherman. He served with brilliant distinction during China’s greatest civil war, the 14-year-long Taiping Rebellion, which claimed millions of lives.

Tso was utterly ruthless. He smashed the Taiping rebels in four provinces, put down an unrelated revolt called the Nian Rebellion, then marched west and reconquered Chinese Turkestan from Muslim rebels.

…The Taiping Rebellion — a movement that in part advocated Christian doctrine — nearly toppled the Qing dynasty. It was founded by Hong Xiuquan, a Chinese mystic who believed he was the younger brother of Jesus. The whole astonishing episode has been described admirably by Yale scholar Jonathan Spence in his ‘God’s Chinese Son.’ (Norton, 1996).

…The Taiping Rebellion was the greatest upheaval in 19th century China. It caused massive displacements and shifts in population. Hundreds of thousands of people fled or emigrated, many to America, where they worked building the transcontinental railroad, which was completed in 1869.

I had absolutely no idea!