According to The Flag Foundation of Nigeria, the central vertical white stripe of Nigeria's flag represents peace and unity, and it alludes as well to the Niger River, which flows through the country and gives it its name. The green stripes that flank the white section symbolize Nigeria's lush agriculture.
Nigeria informally adopted this flag design in 1959. It was conceived by a Nigerian engineering student resident in London, Michael Taiwo Akinkunmi. He submitted his proposal after seeing an advertisement for the national flag competition while reading a Nigerian newspaper at the library. According to Akinkunmi, he was inspired by the sight of Nigeria's green fields laid out below as he flew off to England.
Originally, the design included a stylized red sun with alternating long and short rays in the central white section, but the judges omitted this element. Akinkunmi's flag was chosen from among nearly 3,000 entries. The prize of 100 pounds was awarded to him at the Nigerian embassy in London.
Nigeria became an independent nation on Oct. 1, 1960. On the same day, at precisely 12:00 a.m., Akinkunmi's green and white design was run up the flagpole as the country's official flag, replacing the flag of Great Britain.