Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock () or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Petroleum first saw widespread use in the transporation industry as a lubricant. It was refined into various products depending on which part of the engine they were meant to lubricate. It was transported in tanker cars like this one.
Public Domain.
