While researching a topic, a student has taken the following notes:
• In 1897, African American inventor Andrew Beard invented an automatic coupler.
• It improved on the existing design of train car couplers.
• It made the job of connecting train cars safer.
• In 1938, African American inventor Frederick Jones invented a mobile refrigeration system.
• It improved on the existing design of food transport trucks.
• It enabled trucks to carry perishable foods farther.