The title "Mr. President" may apply to persons holding the title of President or presiding over certain other governmental bodies. If the president is a woman, the title "Madam President" is often used. Adopted by President of the United States George Washington as his official manner of address as head of state, "Mister President" was subsequently used by other governments to refer to their heads of state. It has a longer history of usage as the title of the presiding officers of legislative and judicial bodies. It is the conventional translation of non-English titles such as Monsieur le Président for the President of the French Republic.
In micronational world, the title of President is very common in Republics and Democracies and most of the times, it is used to refer ad the Head of State.
Manner of address
The title of president should not be applied anachronistically. For example, when referring to the period before Former President of the United States Ronald Reagan was elected president, he would be referred to as "Ronald Reagan, the Governor of California". Referring to the period after he left office, he would be described as either "Former President Ronald Reagan" or "Ronald Reagan, the Fortieth President of the United States." The phrase "Mr. President" should only be used as a direct address.
Titles for a president's wife have ranged from "Marquise", "Lady" to simply "Ms." "Mrs. President" may denote the wife of a president, although it is not commonly used.
President George Washington's wife, Martha Washington, was often called, "Lady Washington". By the 1850s in the United States, the term "lady" had changed from a title of nobility to a term of address for a respected and well mannered woman. The use of "First Lady" to refer to the wife of the President of the United States was popularized about the time of the US Civil War. Dolley Madison, the wife of President James Madison, was remembered after her death in 1849 by President Zachary Taylor as "truly our First Lady for a half a century."