George Washington was the first president of the United States of America. He main achievements were the precedents they first were he only served two 4 year terms, and the second precedent was establishing a cabinet.
Which set the standards for future presidents to come.

John Adams main success was the XYZ affairs.
The XYZ Affair was a diplomatic incident between French and United States diplomats that resulted in a limited, undeclared war known as the Quasi-War. U.S. and French negotiators restored peace with the Convention of 1800, also known as the Treaty of Mortefontaine.

Thomas Jeffersons main success was the Louisiana purchase. The reason that the Louisiana purchase was so important was because he doubled the size of the United States or America.

James Madison's major victory was the war of 1812. The war was fought along the Canadian border. The American fleet won control of Lake Erie and created a stalemate on Lake Ontario. During the war the British burned down many buildings in Washington, DC, but were defeated at Baltimore's fort.

James Monroe's most successful venture was the Monroe doctrine. The Monroe Doctrine was a US foreign policy regarding Latin American countries in the early 19th century. It stated that further efforts by European nations to colonize land or interfere with states in North or South America would be viewed as acts of aggression, requiring U.S. intervention.

John Quincy Adams major effect was that During his term, he worked on developing the American System, consisting of a high tariff to support internal improvements such as road-building, and a national bank to encourage productive enterprise and form a national currency.

Andrews Jackson's major event was the nullification crisis. The Nullification Crisis was a sectional crisis during the presidency of Andrew Jackson created by South Carolina's 1832 Ordinance of Nullification.