Which of the following sentences is correct?

1. For nearly 30 years he **has tried** to persuade the Commission to let him walk across the Falls. At last he has been granted permission.
2. For nearly 30 years he **has been trying** to persuade the Commission to let him walk across the falls. At last he has been granted permission.

Which of the first sentences are correct? Or are both correct? And what are the differences?

Thank you in advance for your answers.