When did oil become important?

Oil became important in the late 19th century, particularly with the advent of the internal combustion engine and the rise of the automobile industry in the early 20th century. The discovery of significant oil reserves, like those in Pennsylvania in 1859, catalyzed its use for lighting and lubrication. By World War I, oil had become crucial for military operations, and its importance continued to grow throughout the 20th century as it became a primary energy source globally. Today, oil remains a key driver of the global economy and energy infrastructure.