Complex sentence: The first issue was published in 1935, three years after the weird menace genre had begun with "Dime Mystery Magazine", and the "Horror Stories" title went on to become one of the major pulp magazines of the 1930s.
Split into simpler sentences: The first issue was published in 1935, three years after the weird menace genre had begun with "Dime Mystery Magazine". The "Horror Stories" title went on to become one of the major pulp magazines of the 1930s.