New York Consolidated Laws, Civil Rights Law - CVR § 43. Discrimination by labor organizations prohibited

As used in this section, the term “labor organization” means any organization which exists and is constituted for the purpose, in whole or in part, of collective bargaining, or of dealing with employers concerning grievances, terms or conditions of employment, or of other mutual aid or protection. No labor organization shall hereafter, directly or indirectly, by ritualistic practice, constitutional or by-law prescription, by tacit agreement among its members, or otherwise, deny a person or persons membership in its organization by reason of his race, creed, color or national origin, or by regulations, practice or otherwise, deny to any of its members, by reason of race, creed, color or national origin, equal treatment with all other members in any designation of members to any employer for employment, promotion or dismissal by such employer.