 While living in Brownsville, López began working various jobs to bring in income and never returned to school.As a young man, López caught the attention of a boxing promoter, and for seven years he traveled the country fighting a total of 55 fights in the lightweight division with the nickname of "Kid Mendoza".In 1934, during a boxing match in Melbourne, Victoria, Australia, he met a group of Merchant Marines and signed a contract with them.