Several companies attempted to create a portable laptop during the 1970s and 1980s. The "true" first laptop depends on what features a laptop must have to be considered a "laptop."
Xerox attempted to created the first commercial portable computer with the Dynabook during the 1970s, but most of its potential features were not possible with the technology of the time, such as wireless networking.
Osbourne Computers introduced the first commercially available and successful laptop computer in 1981, called the Osbourne I. While a success--the Osbourne sold 10,000 units in its first month--it was bulky and contained no battery, thus it was not easy to transport.
The GRID Compass, released in 1982, was the first laptop to feature a folding screen and battery power.
First Truly Portable Laptop
In 1987, the US Air Force offered a hefty contract to the first manufacturer that could produce a lightweight laptop--at this time, laptops were quite heavy. Zenith Data Systems won this bid and became the largest laptop manufacturer of the 1980s.
Xerox's Dynabook probably had the most effect on the modern laptop. Alan Kay, lead designer of the Dynabook, worked on features that would be perfected decades later, such as flat-screens and the Graphical User Interface.