What industry saw the greatest increase in female workers

The aviation industry.

Explanation:

During the Second World War, American women entered the workforce in huge number. The percentage of women working in the industrial labor force in the period between 1940 and 1945 raised from 27 % to nearly 37 %. Though women were employed in a variety of positions, the highest increase in female workers was seen by the Aviation industry. More than 310,000 women were engaged in the aircraft industry of the United States in the year 1943 that made a total of 65 per cent of the total workforce.