Many of those departments are completely unnecessary. Was the US really at risk before the Department of Homeland Security came around after 9/11? Did we learn nothing in school before the Department of Education came around in 1980?
In other words, it wasn't that there was nothing, but rather it was a reshuffling and reprioritizing of what was already there.
Do you also think that before the DoD was created in 1949 that there was no federal response to defense?
Or do you justify even bad logic in support of your view of how the government should work?