Quick search by citation:

28 U.S. Code § 1451 - Definitions

For purposes of this chapter—
(1)
The term “State court” includes the Superior Court of the District of Columbia.
(2)
The term “State” includes the District of Columbia.
(Added Pub. L. 91–358, title I, § 172(d)(1), July 29, 1970, 84 Stat. 591.)
Statutory Notes and Related Subsidiaries
Effective Date

Section effective first day of seventh calendar month which begins after July 29, 1970, see section 199(a) of Pub. L. 91–358, set out as an Effective Date of 1970 Amendment note under section 1257 of this title.