Although the concept was envisioned by AT&T, Martin Cooper is credited with inventing the cell phone. Essentially, Cooper focused on creating a "car phone" that would become the first cell phone in 1973.
The first cell phone was the size of a brick, weighed 2.5 pounds and was around 11 inches tall. It was demonstrated in April of 1973 by Cooper, who was working for Motorola and placed the first cell phone call to the head of rival AT&T's cellular program. The cell phone was not available for commercial sale for another decade.
Notably, Cooper went on to invent the Jitterbug, which is a simplified version of the cell phone that is marketed to seniors.