How to use "defend" in a sentence

I trust this will not be regarded as a menace, but only as the declared purpose of the Union that it WILL Constitutionally defend and maintain itself.

YOU have no oath registered in heaven to destroy the government, while I shall have the most solemn one to "preserve, protect, and defend it."

The rebels fought long and hard to defend the stronghold, but finally they had to withdraw to the low wall outside the wine shop

She never tried to defend herself and even got quite annoyed when she realized people thought she was mad