N.H. Rev. Stat. § 467:4
Any person or corporation owning or having introduced wild boar into this state who shall have suffered, permitted, or otherwise failed to prevent the escape of such wild boar shall abate, at his or its own expense, the public nuisance resulting therefrom on or before April 1, 1950, by employing all reasonable means to capture or exterminate such wild boar and their progeny. Persons suffering damage to their lands, property or person after April 1, 1950, caused by wild boar at large as specified in this section, and which are not captured or exterminated as herein provided within the specified time limit, may recover such damage in an action of trespass against the said owner, or person or corporation having introduced the same into this state.
RSA 467:4
1949, 294:2, eff. July 22, 1949.