Lower case "jeep" was a nickname like a pickup, scooter, tank etc... that was used for a few different vehicles but really stuck with the 1/4 ton 4x4 built by Willys & Ford. After WWII (and a long legal battle) Willys trademarked the name "Jeep" and it has been passed along through several manufactures to date. Correctly the WWII models are jeeps and after that Jeeps. Minor point...unless you own the name of course.