Travel Nursing-- Do I need my license in state beforehand?

[I_Witchfinder]

Hello all. I am a nurse looking into travel nursing positions. On the first website I looked into I noticed that a requirement for the position was that I should have my license in the state I am applying to work in. Is there a travel nursing agency that doesn't necessarily require you to apply for your license in a state beforehand? I mean if I were intending to nurse all over the country it would seem a bit tedious to have to be applying for a nursing license transfer (and not to mention expensive if the state requires a fee) if I want to apply at a lot of different positions and see which one sticks. Or am I thinking about this all wrong? Please enlighten me. Thank you.