The first African-American to be awarded the National Medal of Technology, Frederick McKinley Jones invented a method of mobile refrigeration which consisted of a small compressor unit attached to delivery trucks allowing perishable foods to be transported over long distances.

Prior to Jones' invention in 1938, salt and ice were used, an unreliable method that often led to food spoiling before it reached its destination. Jones co-founded the Thermo King Corporation, which produced the mobile refrigeration unit. The business expanded globally and was clocking up annual sales in the region of $1 billion when it was sold in 1997, the equivalent of around $2 billion (£1.5bn) in today's money.

Little-known innovators who changed the world