Atlantic Group founder Michael Leiderman dies of ALS

The business man and baseball entrepreneur was 56


Michael Leiderman, formerly of Merrick, died of complications of ALS on Nov. 19. He left behind a Long Island baseball legacy and inspirational business ethics, his family said.

“My father was the most incredible businessperson I’ve ever seen,” Leiderman’s daughter, Erica Kleinstein, said.

Leiderman, 56, was the owner and co-founder of the Atlantic Group, a company specializing in supplying businesses with furniture, whether it was filling entire offices or helping young businesses furnish small spaces. The Atlantic Group flourished under Leiderman’s guidance thanks to his personal and friendly business approach, Kleinstein said.

The business grew into a family venture when Kleinstein, now 27, shadowed her father on the job in 2011. She went from an inexperienced and unsure businessperson to adopting her father’s skill set, becoming the vice president of sales for Atlantic in 2013.

“In 2013, I graduated college and didn’t know what to do,” Kleinstein said. “When I had the opportunity to actually work with him, I saw a different side of him. I found out that me and him are very similar in ways I didn’t realize before.”

Leiderman taught her to put “friendship first” when meeting prospective clients, she said. His goal was to create long-lasting relationships with customers while emphasizing loyalty and trust. He came across as a “lovable guy,” she said.

“He always found a way to be positive,” Kleinstein added. Even when pursuing business ventures that fell through, he was never negative, she said.

Beyond his business, Leiderman was defined by his love of baseball. Every day of his children’s early lives had baseball-themed moments, Kleinstein and her brother, David Leiderman, said.

“As soon as I was born, I was brought up to bat,” David, 24, said. A batting cage in the back of the Leiderman home kept baseball a constant factor in their lives. Michael shared his love of the sport through his baseball academy, Long Island Storm.

Storm began as a baseball team, the Long Island Brewers, but eventually added an academy, instructing players as young as 8. College-aged and older, formerly professionals played on the Storm team, and Leiderman put no limits on where they played. He funded trips to face off against national teams in British Columbia, Cuba, the Dominican Republic, Italy and Spain, David said.

According to the Storm’s website, by 2010 the team had won 43 national tournaments and 11 national titles and championships. It had a record through the years of 1,387 wins and 315 losses — a .797 winning percentage. More than 100 professional players have been involved in the organization.

“We’ve played all over the world,” Leiderman wrote on the website. “The win over Cuba ranks as one of our greatest accomplishments in a lifetime of memories.”

Leiderman’s influence on his son, who played for Storm briefly, led David to even greater baseball heights. Last year he joined the Miami Marlins.

“It was both mine and his dream,” David said. “Unfortunately, he wasn’t able to see my first game in person, but I know it meant the world to him. He was very excited.”

Leiderman pushed his daughter to pursue baseball when she was younger, too, and she became the first girl to play in the Merrick Little League.

Seeing their father struggle with the disease was difficult for Erica and David, but he remained strong until the end, they said. He had ALS for four years, and the disease gradually weakened his muscles and confined him to a wheelchair.

“It was especially difficult to watch someone so powerful dwindle in health and to watch it hinder him physically,” Erica said.

In Leiderman’s honor, his family asks that people donate to the ALS Association. The donation page opened in his name had accumulated nearly $15,600 by press time. Visit the page at

Leiderman is also survived by his wife of 30 years, Galita Leiderman, and his sister, Caren Samplin.