<Tr> <Th_colspan="2"> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> Federal Penetration up the Cumberland and Tennessee Rivers </Th> </Tr> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> <Tr> <Td_colspan="2"> <Ul> <Li> Fort Henry </Li> <Li> Fort Donelson </Li> <Li> Shiloh </Li> <Li> Corinth </Li> </Ul> </Td> </Tr> <Ul> <Li> Fort Henry </Li> <Li> Fort Donelson </Li> <Li> Shiloh </Li> <Li> Corinth </Li> </Ul>

What was the geographic significance of the forts henry and donaldson