Final answer:
General Douglas MacArthur ignored President Hoover's orders to leave the shantytowns of protesting veterans alone by forcibly removing the protesters and destroying their encampment, resulting in casualties.
Step-by-step explanation:
The military figure who ignored Hoover's orders to refrain from clearing out the shantytowns was General Douglas MacArthur. President Herbert Hoover initially ordered the police to disband the Bonus Army, a group of veterans demanding their owed bonuses, from federal buildings.
The situation escalated, leading to police opening fire on the veterans, killing two. Concerned about an armed rebellion, Hoover tasked MacArthur to disband the protesters. However, MacArthur defied Hoover's limits and not only removed the veterans but also ordered the destruction of their shantytown in Anacostia Flats.
Aided by Major George S. Patton and Major Dwight Eisenhower, MacArthur's actions led to numerous injuries and the death of an infant due to tear gas exposure.