Petered out is a colloquial slang expression for something that withered away and slowly faded out of existence, despite people screaming passionately Don’t Let the Flame Die Out.
Although the exact origin of the phrase is not known, it comes from the lingo of miners in the United States, who used the word “peter” with the meaning “to exhaust” by the 1810’s.
The first documented case of “Petered out” appearing in print comes from the 1832 “Records and Briefs of the United States Supreme Court”.
Over the remaining decades of the 1800’s, “Petered out” spread further with the booming industries, set on track by the industrial revolution going in full swing across the whole United States.
Its popularity grew even further in the 20th century, appearing in all sorts of contexts until the middle of the century, when it slowly began to decline.
Although today it is not nearly as widely used as it was a hundred years ago, it may still be encountered, especially in rural areas of the United States.