N.Y. R.R. Law § 50
An action may be maintained against any railroad corporation by any laborer for the amount due him from any contractor for the construction of any part of its road, for ninety or any less number of days' labor performed by him in constructing such road, if within twenty days thereafter a written notice shall have been served upon the corporation, and the action shall have been commenced after the expiration of ten days and within six months after the service of such notice, which shall contain a statement of the month and particular days upon which the labor was performed and for which it was unpaid, the price per day, the amount due, the name of the contractor from whom due, and the section upon which performed, and shall be signed by the laborer or his attorney and verified by him to the effect that of his own knowledge the statements contained in it are true. The notice shall be served by delivering the same to an engineer, agent or superintendent having charge of the section of the road, upon which the labor was performed, personally, or by leaving it at his office or usual place of business with some person of suitable age or discretion; and if the corporation has no such agent, engineer or superintendent, or in case he can not be found and has no place of business open, service may in like manner be made on any officer or director of the corporation.
N.Y. R.R. Law § 50