Can I do this (do a marathon (half marathon) in all fifty states in a year) myself?
I have been asked this several times. A glib response is if you have to ask, you probably can't. But assuming they are capable, and just seeking as much knowledge as they can before embarking, here we go.
If you are an AB (able bodied) runner, sure, there are organizations that are dedicated to finishing races in all the states and/or doing a lot of races in a year. Join one or more, use their tools and start training.
I'm going to concentrate on the people with physical deficits, it is a challenge. First, there many races at which we are not welcomed. AB's have all kinds of options, we have have to go where and when to the races that will have us. Scheduling is a huge challenge.
"Myself" is a loaded term in the adaptive sports world. We have equipment, tools, everyday wheelchairs to/from starting/finishing lines. The methods to mark the course is often better for runners than wheelers.
As impolite as it is to answer a question with a question, I'll do it now. How have you done at supported races? By supported races, I mean races that either the race organization or third party organizations help with transportation of wheelchairs, transfers, etc. Not all races provide support, some do. Achilles International is an organization that provide support at some races.
If you did well at the supported races, then you have a chance at the "unsupported" races. Also, the less support you actually need in the supported races, the better your chance of completing an unsupported race. In general, unsupported races are more common. What I mean by unsupported races is races that allow us to participate and probably they do nothing more than maybe let us start first. We are responsible for getting our gear and everyday chairs to where we need them to be. You can self support like I do when needed, or bring your own support team (family, friends, ne'er do wells performing community service, etc.). If you can't self support, your expenses go up, more people to get to and from the races.
To undertake a 50 state plan I think it is important to be able to:
Maintain your hygiene and health while traveling.
Know the signs of when you need to seek medical attention from complications from your physical deficits.
Know your body and what foods/fuels you need before, during, and after travel and races.
Do routine maintenance on your racing chair. (You'll be in different states and cities where you may not be able to find help to fix or make adjustments).
Improvise repairs before and during the race. (Scheduling is tight, a DNF (did not finish) makes you come back later, and in some states that may not be possible. Equipment failure may make you incredibly slow, but if you can persevere, you can get the finish).
Problem solve when your hotel room is not as accessible as you need it to be.
Be organized with schedule and travel plans.
Be able to undertake extensive travel.
Tolerate (understand what you must do in) inclement weather (heat, cold, wind, rain, snow, and sun).
It is a little of a chicken and the egg problem. You will definitely get better at all of the above skills as you do a 50 state plan. I just recommend some trial trips first to know what you are undertaking.