besieging vs Petersburg Campaign

besieging and Petersburg Campaign both are nouns.

Word	Noun	Adjective	Verb	Adverb
besieging	Yes	No	No	No
Petersburg Campaign	Yes	No	No	No

besieging (noun)	Petersburg Campaign (noun)
the action of an armed force that surrounds a fortified place and isolates it while continuing to attack	the final campaign of the American Civil War (1864-65); Union forces under Grant besieged and finally defeated Confederate forces under Lee