Martha Clark grew up in Kansas and eventually married local farmer Jonathan Kent. They lived together for decades but were unable to have children of their own. One day, while Jonathan and herself were out driving, they found a three year old boy in a space ship. They adopted him and named him Clark Kent, after Martha's maiden name. Shortly after her husband's death, Clark left on his journey to become Superman.
Before leaving Clark he arranged for Ben Hubbard to help out on the farm. While Clark was working for the Daily Planet in Metropolis, Clark arranges with his boss Perry White, to have half of his salary sent to Martha, showing that he continued to support his widowed mother in her old age. Eventually Martha passed away.