NEW MILFORD — Joel Levitt grew up knowing that his grandparents left Ukraine and Belarus for better lives in America around the turn of the 20th century.

It wasn’t until he became a grandparent himself though that he decided to dive deeper into their stories and write his recently published book, “The Tree of Lives.” The book focuses on the stories of his family from the late 1800s to 1973 when he and his wife, Barbara, married. It also looks at broader experiences other European immigrants faced during that time.

“That larger picture resonates with people that have these shared experiences,” said Levitt, 70, of New Milford and a retired Danbury teacher. “It’s about the human experience.”

Levitt hopes his book will help his grandchildren understand their humble roots and the sacrifices their ancestors made. His granddaughters, Briella and Haley, and grandson, Joey, are even pictured on the book’s cover.

“How will they know where they are going if they don’t know where they came from?” he said.

He also hopes readers can see parallels to their own families with the experiences shared in his book. He’s already seen this happen and has had people share their stories and old family photos at book signings.

Both of Levitt’s grandfathers came to the U.S. years before his grandmothers followed with the children. In the meantime, they would send money back home.

Levitt said his grandparents never spoke about their experiences before coming over and so he’s had to supplement their stories with research of what European immigrants on a broader scale at that time would have dealt with. He was able to find the name and dates of the ship they arrived on and then researched other accounts from that boat and Ellis Island.

“They had terrible lives in the old country and didn’t want to bring that terror into the new country,” Levitt said.

He was able to get a lot of help from Facebook groups where other Jewish people interested in genealogy could translate the travel documents from the Yiddish, Russian and French — none of which Levitt speaks. He said it was common at the time for the immigrants who arrived in the U.S. to switch to only English with their children, removing the language more with each generation.

“That language was lost to the third generation — my generation,” he said.

While researching the book, he reconnected with cousins he hadn’t seen in years to get their stories. He and his wife also did a DNA test with Ancestry, the genealogy database, and learned of hundreds of people they were biologically related to. He reached out to the 100 people with the strongest connections and heard back from 40. They then traced the family tree back and found common names with six of them, including a woman who was adopted and had recently discovered her biological family.

Levitt said his mother would share old photos and names of relatives with him, but he was able to learn a little more about those people while researching, including Zachary Solov, a dancer and choreographer at the Metropolitan Opera Ballet.

Solov hired Janet Collins as a prima ballerina, making her the first African American artist under regular contract at the Metropolitan, four years before Marian Anderson performed there, according to his obituary in the New York Times.

“The whole thing has been a wonderful ride,” Levitt said. “I’m having so much fun.”

He will be signing copies of his book at Barnes and Noble in Danbury from 1 to 3 p.m. on Saturday.