Should I capitalize the word “is” on my essay title?

if its the first word yes. if its just in between words no

In the title of an essay or article words with less than 3 letters are not capitalize. However if "is" is at the beginning of your title then you should capitalise it.

the statement that best explains why the tenth amendment reserves some rights and powers to states is that the framers believed in the principle of federalism. this principle says that some powers are in the hands of a centralized national government, while others are reserved for the governments of several states.

b. the poet identifies with private people.

    in the stanza, dickinson states she doesn't wish to seek fame and recognition from the public eye. nor is she afraid of authority figures, and you can definitely tell she isn't hiding something. more as she identifies with private people, who are not known by the community