Question

Is there a sentence fragment?

At the conclusion of the War of 1812, the youngest general in the army was Winfield
Scott. Whose tactical methods and regulations came to define the U.S. Army for most of
the nineteenth century.
yes
no

Answer 1

Yes. The second sentence is incomplete as there is no subject. Both sentences should be connected together with a comma.

At the conclusion of the War of 1812, the youngest general in the army was Winfield Scott, whose tactical methods and regulations came to define the U.S. Army for most of the nineteenth century.