Charles G. Blake was born around 1841 in New Hampshire to Horatio Blake and Rebecca Berkley. His father was a farmer who owned $1,000 of real estate and $500 of personal property by 1860. The family lived in Hill, New Hampshire, until the 1850s, when they moved to Royalton, Vermont. By the early 1860s, he was living in Greenfield, Massachusetts, and working as a telegraph operator for the Vermont Central Railroad.
He enlisted in the Union army on July 15, 1862, and mustered in as a sergeant in Company F of the 34th Massachusetts Infantry on July 31. The regiment took part in the Third Battle of Winchester, the Battle of Cedar Creek, the siege of Petersburg, and the Appomattox campaign. In 1864, Blake earned a series of promotions: to sergeant major on April 28, to 2nd lieutenant on June 6, and finally to 1st lieutenant on October 18. In January 1863, he declared that the "Proclamation of abolition though seemingly of little use now will I think be productive for great good. With Gen [Benjamin] Butler many have turned abolitionists since coming here. Let the pro slavery men of the north come down here and observe the beauties of Slavery and they will go back wiser and better men." He mustered out in Richmond, Virginia, on June 16, 1865.
Blake began courting Mary Cowdery around 1863, and they got married on February 7, 1867, in South Royalton, Vermont. They settled in Manchester, New Hampshire, and Blake continued to work as a telegraph operator. Around 1875, the Brazilian government contracted him to build a telegraphic fire alarm system for Rio de Janeiro. He died there of yellow fever on April 11, 1876.