2. This word is usually applied to those acts of the legislature, which
are made to operate upon some subject, contract or crime which existed before
the passage of the acts, and they are therefore called retrorospective laws.
These laws are generally unjust and are, to a certain extent, forbidden by that
article in the constitution of the United States, which prohibits the passage
of ex post facto laws or laws impairing contracts.
3. The right to pass retrospective laws, with the exceptions above
mentioned, exists in the several states, according to their own constitutions,
and become obligatory if not prohibited by the latter. 4 S. & R. 364; 3
Dall. R. 396; 1 Bay, R. 179; 7 John. R. 477; vide 4 S. & R. 403; 1 Binn. R.
601; 3 S. & R. 169; 2 Cranch. R. 272 2 Pet. 414; 8 Pet. 110; 11 Pet. 420; 1
Bald. R. 74; 5 Penn. St. R. 149. 4. An instance may be found in the laws of
Connecticut. In 1795, the legislature passed a resolve, setting aside a decree
of a court of probate disapproving of a will and granted a new hearing; it was
held that the resolve not being against any constitutional principle in that
state, was valid. 3 Dall. 386. And in Pennsylvania a judgment was opened by the
act of April 1, 1837, which was holden by the supreme court to be
constitutional. 2 Watts & Serg. 271.
5. Laws should never be considered as applying to cases which arose
previously to their passage, unless the legislature have clearly declared such
to be their intention. 12 L. R. 352 Vide Barringt. on the Stat. 466, n. 7 John.
R. 477; 1 Kent, Com. 455; Tayl. Civil Law, 168; Code, 1, 14, 7; Bracton, lib.
4, fo. 228; Story, Cons. §1393; 1 McLean, Rep. 40; 1 Meigs, Rep. 437; 3
Dall. 391; 1 Blackf.R.193; 2 Gallis. R. 139; 1 Yerg. R. 360; 5 Yerg. R. 320; 12
S. & R. 330; and see Ex post facto.
Source: Bouviers Law Dictionary 1856 Edition