States definitely vary in the elements of rape, but here's the Massachusetts version and I imagine every state has a similar reference:
"The crime of rape consists of two elements.
First Element: that the defendant engaged in sexual intercourse, either natural or unnatural, with a person; and
Second Element: that the sexual intercourse was accomplished by compelling such person to submit by force or threat of bodily injury and against (his/her) will. . . .
The second element of rape is that the natural or unnatural sexual intercourse is accomplished by force or threat of bodily injury and against the person's will. What does it mean when I say the sexual intercourse was "against the person's will?" By this I mean that at the time of penetration, the complainant did not consent. "