Here's the full definition that you cherry picked from:
(1) the term “international terrorism” means activities that—
(A) involve violent acts or acts dangerous to human life that are a violation of the criminal laws of the United States or of any State, or that would be a criminal violation if committed within the jurisdiction of the United States or of any State;
B) appear to be intended—
(i) to intimidate or coerce a civilian population;
(ii) to influence the policy of a government by intimidation or coercion; or
(iii) to affect the conduct of a government by mass destruction, assassination, or kidnapping; and
(C) occur primarily outside the territorial jurisdiction of the United States, or transcend national boundaries in terms of the means by which they are accomplished, the persons they appear intended to intimidate or coerce, or the locale in which their perpetrators operate or seek asylum;
So, under that criminal code that you quoted, were the actions on Capitol Hill international terrorism?
> ... acts dangerous to human life ... [intending] ... to influence the policy of a government by intimidation or coercion ...
[0] https://www.law.cornell.edu/uscode/text/18/2331