He worked to protect copyrights of his Nobel Prize-winning father, writer John Steinbeck.

LOS ANGELES — Thomas Steinbeck, the eldest son of Nobel Prize-winning author John Steinbeck and a prominent author and screenwriter in his own right, died Thursday at his Santa Barbara home. He was 72.

“The Grapes of Wrath” author’s son, who was working on a memoir at the time of his death, died of chronic obstructive pulmonary disease, according to a statement from his family.

In addition to being a writer, Steinbeck fiercely defended his father’s work, adapting several John Steinbeck books for movies and launching legal efforts to protect the copyrights of his father and others.

“Until the end, Thom worked to protect his father’s name and legacy, as well as the rights of creative individuals everywhere,” Steinbeck’s wife, Gail, said in a statement to The Associated Press.

She called her Vietnam War veteran husband a patriot as well as a “wonderful, loving husband and son.”

After years as a documentary filmmaker and screenwriter, Steinbeck launched his own career as an author relatively late in life. At age 58 in 2002, he published his first book, a collection of stories called “Down to a Soundless Sea” to positive reviews. He followed it with the novels “In the Shadow of the Cypress” in 2010 and “The Silver Lotus” in 2011.

Like his father’s works, many of the younger Steinbeck’s stories were set along California’s picturesque coastline.

“Down to the Soundless Sea” recounts tales of early settlers in Big Sur while “In the Shadow of the Cypress” was set in Monterey, the same coastal city Steinbeck’s father used as settings for the novels “Sweet Thursday,” “Cannery Row” and “Tortilla Flat.”

Steinbeck, who bore a striking resemblance to his father, launched a nearly decade-long battle in 2004 to claim intellectual property rights to written works he said should have been passed on to him and his family upon his father’s death. In 2009 he and folk singer Arlo Guthrie brought a copyright infringement case against Google that was eventually settled.Thomas Myles Steinbeck, known to friends as Thom, was born in New York City on Aug. 2, 1944, to the “East of Eden” author and his second wife, singer-composer Gwyndolyn Steinbeck. The couple divorced four years later and he was raised mainly in East Coast boarding schools.

He often spent summers and holidays with his father, traveling through Europe, Greece and North Africa or vacationing in Pacific Grove, California, and Sag Harbor, New York.

It was during those times, he said, that his father imparted in him a passion for writing. From his mother, he said, he gained a deep appreciation for art.

Steinbeck was preceded in death by his parents and younger brother, John IV.