Nigeria is an amalgam of ancient Kingdoms, Caliphates, Empires and City-states with a long history of organized societies. Its boundaries were drawn as a result of trade (from slavery to pepper or ivory) and overseas territorial ambitions of Western European powers in the 19th century. The name Nigeria was adopted in 1898 to designate the British Protectorates on the River Niger.

The National Coat of Arms and Its Meaning

The top of the coat of arms is an eagle, red in color, depicting Nigeria’s strength. The eagle is mounted on a wreath which is rendered in the national colors.
The eagle and wreath rest on a shield. The shield, black in color, signifies the fortuitous qualities of the land in cultural, mineral and solid resources.
The Y-shaped, silver- colored wavy band in the middle of the shield represents the two major rivers in the country viz. River Niger and River Benue. 
Two white horses support the shield on either side. These signify dignity. The base upon which the shield rests is Coctus spectabilis, a wild flower that grows in many parts of the country.
Underneath all of these is the motto of the country which reads: “Unity and Faith, Peace and Progress.”
 

The National Flag

Nigeria’s flag is a rectangular strip divided into three equal parts viz. green, white and green. The green depicts the country’s land and agriculture potential while the white depicts peace and unity. It may be useful to note that the two horizontal edges are longer than the vertical edges.

The National Anthem
Arise, O compatriots Nigeria’s call obey
To serve our fatherland
With love and strength and faith
The labour of our heroes past
Shall never be in vain
To serve with heart and might
One nation bound in freedom
Peace and unity.

O God of creation, direct our noble course
Guide thou our leaders right
Help our youth the truth to know
In love and honesty to grow
And living just and true
Great lofty heights attain
To build a nation where peace
And justice shall reign.

The national anthem was adopted in October 1978 and the music was composed by Mr. Ben Odiase the director of music, Nigeria police band.
The national pledge
I pledge to Nigeria, my country
To be faithful, loyal and honest,
To serve Nigeria with all my strength
To defend her unity
And uphold her honor and glory
So help me God.

Six Political Zones of Nigeria: States and Capital

North central                                North East                                 North West
Benue           Makurdi              Adamawa        Yola                    Jigawa           Dutse
Niger             Minna                 Bauchi             Bauchi                Kaduna          Kaduna
Katsina          Katsina             Borno              Maiduguri            Kano              Kano
Kogi               Lokoja               Gombe             Gombe               Kebbi             Birnin kebbi
Kwara           Ilorin                   Taraba              Jalingo               Sokoto           Sokoto
Nassarawa   Lafia                  Yobe                 Damaturu         Zamfara        Gusau
Plateau         Jos

South West                                   South East                            South South
Ekiti           Ado - Ekiti            Abia           Umuahia                  Akwa - Ibom          Uyo
Lagos        Ikeja                    Anambra    Awka                        Bayelsa                 Yenogoa         
Ogun         Abeokuta             Ebonyi         Abakaliki                Cross River            Calabar
Ondo          Akure                  Enugu         Enugu                     Delta                       Asaba
Osun          Osogbo              Imo             Owerri                      Edo                         Benin
Oyo             Ibadan                                                                     Rivers                      Port Harcourt

Rulers of Nigeria till date
Nigeria has had past Presidents till date and listed below are the Biographies of the Past rulers of Nigeria till date.
  Benjamin Nnamdi Azikwe
  Major General Johnson Thomas Umunnakwe Aguiyi-Ironsi
 General Yakubu "Jack" Dan-Yumma Gowon
  General Murtala Ramat Mohammed
  Shehu Usman Aliyu Shagari
  Muhammadu Buhari
  Major General Ibrahim Badamasi Babangida
  Ernest Adegunle Oladeinde Shonekan 
  General Sani Abacha 
  General Abdulsalami Alhaji Abubakar (rtd.) 
  Olusegun Mathew Okiola Aremu Obasanjo
  Umaru Musa Yar'Adua
  Goodluck Ebele Azikiwe Jonathan

Source: Wikipedia