Don Valentine, a venture capitalist who founded Sequoia Capital, a Silicon Valley venture capital firm that helped cement the area’s rise as a technology hub, died on Friday at his home in Woodside, Calif. He was 87.

Mr. Valentine died of natural causes, a spokeswoman for Sequoia said.

Mr. Valentine’s career spanned four decades and included roles at the chip maker Fairchild Semiconductor, regarded as Silicon Valley’s original start-up, and National Semiconductor, which was spun out of Fairchild. In 1959, when he joined a silicon company, “the word ‘Silicon Valley’ hadn’t been created yet,” he said in an interview at a technology conference in 2013.

In 1972, Mr. Valentine established Sequoia, and it soon became one of Silicon Valley’s most successful and enduring firms. Sequoia backed companies including Oracle, Microchip Technology, Linear Technology and Network Appliance. Several tech giants, including Electronic Arts and Sierra Semiconductor, were created in Sequoia’s offices.

Mr. Valentine invested in Atari in 1975, and three years later, he wrote a $150,000 check for Apple Computer. He also invested in Cisco Systems and was the networking equipment company’s chairman for three decades.