fair trial and appointments

[kjc0123]

What is the meaning of "be given a fair trial" and "appointments" in the following sentences?

The principle of separation of powers had already been given a fair trial in most state constitutions and had proved sound. Accordingly, the Convention set up a governmental system with separate legislative, executive and judiciary branches -- each checked by the others. Thus congressional enactments were not to become law until approved by the president. And the president was to submit the most important of his appointments and all his treaties to the Senate for confirmation. The president, in turn, could be impeached and removed by Congress. The judiciary was to hear all cases arising under federal laws and the Constitution; in effect, the courts were empowered to interpret both the fundamental and the statute law. But members of the judiciary, appointed by the president and confirmed by the Senate, could also be impeached by Congress

[mrs.pudding]

In this case 'A fair trial' means that the principle had been used in several States under various conditions and had been found to work.

"Appointments" refer to the people that the President has given government jobs to.