Some interesting O-1 Visa facts that may help you:
Consultations/Written Advisory Opinion
Generally speaking, a consultation/written advisory opinion is required from a labor union before an O-1 visa petition may be adjudicated. If a union has a collective bargaining agreement in the field, then that is the appropriate union with which to consult.
Otherwise, a union with expertise in the field is appropriate. If there is no labor union in the field, the letter can come from an individual with expertise in the foreign national’s field or a “peer group” with a strong focus on the field.
Full-time or Part-time for O-1 Status
You may apply for an O-1 visa for a full-time position or a part-time position.
O-1 Visa Itinerary
An itinerary describing the dates of each engagement or service, the names and addresses of the organizations or events, and the names and addresses of the establishments, venues, or locations where the services will be performed has become very important in the adjudication of an O-1 visa application, especially if an agent is involved.
The itinerary needs to be provided by the agent or employer and it should be supplemented with any available documentation evidencing the various engagements and the terms and conditions, if possible.
O-1 Visa Transfer
You can transfer your O-1 Visa from one employer or agent to another. There is no limit on the number of O-1 transfer applications that can be filed. When you submit a transfer application, you can only begin working for the new employer or agent when the application is approved.
O-1 Holder’s Spouse & Children
An O-1 visa holder’s spouse and children can apply for O-3 visas based on their relationship to the O-1 holder. O-3 visa holders cannot work in the United States, but they can go to school and they are in legal status while in the United States.
Duration of the O-1 Visa
The O-1 can be obtained for up to a 3 year period for each application. There is no overall time limit on O-1s as there is with the H-1B visa or L-1 visa.
O-1A v. O-1B
The O-1A designation is ued for all O-1 applications that fall within the sciences, arts, education, business or athletics. The O-1B designation is for individuals in motion picture or TV production. See the above Q & A for an overview of the criteria for each.
From O-1 to Green Card Permanent Residency
For some individuals, an O-1 may be a prelude to a self-sponsored EB-1 green card application.
Of course, an O-1 may be eligible for an employment based green card through the EB-2 and EB-3 categories as well, but unless applying through the “National Interest Waiver” sub-category, these categories will require employer sponsorship unlike the EB-1 category. Just like the vast majority of most other nonimmigrant status holders, an O-1 can apply for a green card through marriage to a United States citizen.
For more info on the options available for a marriage green card, see the following: marriage green card process.