What is the origin of the phrase "the great unwashed" referring to the general public?

Origin of "The Great Unwashed"
The phrase "the great unwashed" is said to have its initial usage in Edward Bulwer-Lytton's novel, Paul Clifford, published in 1830. In that book, the phrase goes thus; "He is certainly a man who bathes and 'lives cleanly', (two especial charges preferred against him by Messrs. the Great Unwashed)." Since then, the phrase has been used by many authors conveying different nuances.