The 33-Star Flag: This Flag became the Official United States Flag on July 4th, 1859. A star was added for the admission of Oregon (February 14, 1859) and was to last for 2 years. The two Presidents to serve under this flag were James Buchanan (1857-1861) and Abraham Lincoln (1861-1865).
The 34-Star Flag: This Flag became the Official United States Flag on July 4th, 1861. A star was added for the admission of Kansas (January 29th, 1861) and was to last for 2 years. The only President to serve under this flag was Abraham Lincoln (1861-1865).
The 35-Star Flag: This Flag became the Official United States Flag on July 4th, 1863. A star was added for the admission of West Virginia (June 20th, 1863) and was to last for 2 years. The two Presidents to serve under this flag were Abraham Lincoln (1861-1865) and Andrew Johnson (1865-1869).
The 36-Star Flag: This Flag became the Official United States Flag on July 4th, 1865. A star was added for the admission of Nevada (October 31st, 1864) and was to last for 2 years. The only President to serve under this flag was Andrew Johnson (1865-1869).