For example, the flags of New Jersey, Wisconsin, Maine, Delaware, and New York are quite similar, with two people standing opposite a seal on a solid colored field. Why is this?
Why do so many state flags look so similar?
Many U.S. states created their flags based on their seals or coats of arms. Frankly, since most U.S. states have limited sovereignty, there are not that many situations that call for the use of the state flag, other than outside of government buildings. In situations where it would be important, like a battlefield, most units have their own regimental flags that are more distinctive. Naval use of the state flags is practically unheard of.