This was a common name in classical Greece, and, due to both the saints who carried it and the favourable meaning, it came into general use in the Christian world, being especially popular among Eastern Christians. It was however rare in Britain before the 19th century. Famous bearers include three tsars of Russia (in the Russian form Fyodor) and American president Theodore Roosevelt (1858-1919).
This name was popularized in continental Europe by the works of the 18th-century Scottish poet James Macpherson [1]. Napoleon was an admirer of Macpherson, and he suggested Oscar as the second middle name of his godson, who eventually became king of Sweden as Oscar I. Other notable bearers include the Irish writer and humorist Oscar Wilde (1854-1900) and the Brazilian architect Oscar Niemeyer (1907-2012).
During the 20th century, Graham was more common in the United Kingdom, Australia and Canada than it was in the United States. However, it has been rising on the American charts since around 2006.
As an English name it was highly popular from the Middle Ages until the 17th century. It was revived in the 19th century and was common into the 20th, but it fell into decline after the 1930s. It last appeared on the American top 1000 rankings in 1972.