The new Constitution called for a government of three branches: the executive; the legislative; and the judicial. It fell to Washington to establish the foundation of the government under the Constitution, and the precedents he set are the bedrock of our democracy today.
Search on the good of my country to find the October 26, 1788 letter to Benjamin Lincoln in which Washington discusses the uneasy--and unsolicited--prospect of his election as the nation's first president:
. . . But be assured, my dear Sir, if from any inducement I shall be persuaded ultimately to accept, it will not be (so far as I know my own heart) from any of a private or personal nature. Every personal consideration conspires to rivet me (if I may use the expression) to retirement. At my time of life, and under my circumstances, nothing in this world can ever draw me from it, unless it be a conviction that the partiality of my Countrymen had made my services absolutely necessary, joined to a fear that my refusal might induce a belief that I preferred the conservation of my own reputation and private ease, to the good of my Country.
As the first president, Washington selected the first members of the judicial branch, as well as the members of the president's original cabinet. See the September 25, 1789 "Nominations" letter to the Senate to review Washington's choices for various federal judges, attorneys, and federal marshalls and the Secretary of State, Attorney General, and Post-Master General.
Search on wearied traveler to review Washington's state of mind on the eve of his retirement, at the close of his second term as president. His feelings are contained in a March 2, 1797 letter to his close friend, Henry Knox:
To the wearied traveller who sees a resting place, and is bending his body to lean thereon, I now compare myself; but to be suffered to do this in peace, is I perceive too much, to be endured by some. To misrepresent my motives; to reprobate my politics; and to weaken the confidence which has been reposed in my administration, are objects which cannot be relinquished by those who, will be satisfied with nothing short of a change in our political System. The consolation however, which results from conscious rectitude, and the approving voice of my Country, unequivocally expressed by its Representatives, deprives their sting of its poison, and places in the same point of view both the weakness, and malignity of their efforts. Although the prospect of retirement is most grateful to my soul, and I have not a wish to mix again in the great world, or to partake in its politics, yet, I am not without my regrets at parting with (perhaps never more to meet) the few intimates whom I love, among these, be assured you are one.