Eureka, California
"Eureka" received its name from a Greek word meaning "I have found it!" This exuberant statement of successful (or hopeful) gold rush miners is also the official motto of the State of California. Eureka is the only U.S. location to use the same seal as the state for its seal.
Names of the Greeks
The modern English noun "Greek" (Old English "Grecas" or "Crecas") is derived from the Latin "Graeci", which in turn originates from Ancient Greek ("Graikos"). It seems that the word is related with the Greek word "geron", "old man" (from the PIE base "*ǵerh-", "to grow old") via Proto-Greek "*gera-", "old age"—also related to Mycenean Greek "kera" /geras/, "gift of honour". The Germanic languages borrowed the name with an initial "k" sound, which was probably their initial sound closest to the Latin "g" (Goth. "Kreks").