1. Political parties in the U.S.A.
The Republican Party

2. The Republican Party

3. There are a lot of political parties in the USA.
 The two main ones - the Republican Party and the Democratic Party.
Others
Republican Party
Communist Party, USA
Constitution Action Party
Green Parties of North America
The Libertarian Party
Multi-Capitalist Party
The Natural Law Party
The New Party
Partido Colorado
The Patriot Party
The Reform Party
Socialist Labor Party of America
Socialist Party USA Cybercenter
Third Party Politics
U.S. Pacifist Party
United States Taxpayers' Party
Jerry Brown's We The People
Democratic Party

4. Republican Party. History
The Republican party is popularly known as the GOP, from its earlier nickname of the Grand Old Party. From its first presidential candidate, John C. Fremont, in 1856, through Republican George W Bush in 2000, Republicans have occupied the White House for 84 years.
Abraham Lincoln, the first Republican President (1861–1865)

5. Republican Party. History
"Republicans have a long and rich history with basic principles: Individuals, not government, can make the best decisions; all people are entitled to equal rights; and decisions are best made close to home."
Mission Statement
And what of the nickname "Grand Old Party"?

6. Republican Party Platform.
The Republican platform specifically pledged not to extend slavery and called for enactment of free-homestead legislation, prompt establishment of a daily mail service, a transcontinental railroad and support of the protective tariff. 

7. The approach of the Republicans is best summarized in its lines:
The most effective government is government closest to the people.
Equal rights and equal opportunity for all
Good government is based on the individual person
New ideas, thoughtful change and varying points of view
Free enterprise and encouragement of individual initiative and incentive
National strength and pride
The Republican Party is the best vehicle for translating these ideals into positive and successful principles of government."

8. What else do they believe?
We're fortunate to live in America
You can be what you are, and become what you are capable of becoming
Helping those around you is worthwhile
Small government is a better government for the people
You know what to do with your money better than government
Free markets keep people free
Our Armed Forces defend and protect our democracy