The Canadian passport, the employer's letter, the Ontario registration, the degree and transcript, and any New York licence or board correspondence. Carry originals or clear copies in one folder, ordered the way the officer will ask for them.
Build the folder in the order of the questions
The officer at a port of entry works through citizenship, profession, employer and credential in roughly that order, so the folder should open with the passport, then the employer letter, then the licence and degree. The employer letter needs to say the position is Registered Nurse, describe the duties, state the length of the assignment and the salary, and identify the licence or degree it relies on. If the hospital used a recruitment agency, add a one-page explanation of who pays the nurse and where she reports.
Include the New York board's confirmation if one exists; if the state licence is still pending, include the application receipt and the employer's statement of how she will be assigned in the interim. Leave out relocation packages and benefit summaries, which answer questions the officer has not asked. Keep a copy of everything at home in South Frontenac in case the file must be reconstructed for an extension.
Build a dated index so each claim in the letter points to a record behind it. Hypothetical example: a Canadian biologist is hired to design habitat-monitoring protocols for an environmental consulting firm. The signed offer, a concise duty description, degree evidence, and passport answer separate questions and should not be merged into a promotional package.
If a client will direct the daily work, add the contract that explains the employer's continuing control; otherwise the reviewer may not be able to tell who is actually engaging the professional.