What is the origin of the idiom "come a long way" and when to use it?

The idiom "come a long way" is thought to have originated in the 19th century. It is believed to be a reference to the fact that people used to travel long distances by horse and carriage. The phrase "come a long way" was used to describe someone who had traveled a great distance, and it has since come to mean someone who has achieved great success or made great progress.