Complex sentence: Gautama Buddha died over 2500 years ago, but the oldest Buddhist organization in San Diego County is the Buddhist Temple of San Diego on Grant Hill which was founded by Japanese Americans in 1926 and dedicated at its current location on Market Street in 1931.
Split into simpler sentences: Gautama Buddha died over 2500 years ago, but the oldest Buddhist organization in San Diego County is the Buddhist Temple of San Diego on Grant Hill which is less than 100 years old. It was founded by Japanese Americans in 1926 and dedicated at its current location on Market Street in 1931.