Money raised would be used to pay for funeral expenses and establish a scholarship in Lewis' honor. As of Wednesday morning, nearly $2,000 had been raised.
"It has been truly heartbreaking losing him," a the fundraising Web page says. "He had a big heart and was loved by everyone. His fun-loving spirit, sparkling eyes, and infectious laugh will stay with us forever."
Lewis had been walking in the 1300 block of West Devon Avenue when a gunman opened fire at a rival gang member, police said.
The gunman, who authorities say remains at large, missed his intended target and instead shot Lewis, a bystander, prosecutors said.
Police did arrest and charge Eric Vaughn, of Uptown, in the murder. Vaughn, 31, allegedly gave the gun used in the murder to the shooter as he drove him in his car.
Vaughn had also been released from prison in April after serving seven years for a 2004 attempted murder.
Friends said Lewis was an aspiring fashion photographer with a passion for taking portraits and photos of street scenes. He had recently moved to the neighborhood with his wife, Maria, whom he married in 2012.