The United States of America (commonly abbreviated to the United States, the U.S., the USA, America, and the States) is a federal constitutional republic comprising fifty states and a federal district. The country is situated mostly in central North America, where its forty-eight contiguous states and Washington, D.C., the capital district, lie between the Pacific and Atlantic Oceans, bordered by Canada to the north and Mexico to the south. The state of Alaska is in the northwest of the continent, with Canada to the east and Russia to the west, across the Bering Strait. The state of Hawaii is an archipelago in the mid-Pacific. The country also possesses several territories in the Pacific and Caribbean.

At 3.79 million square miles (9.83 million km²) and with over 312 million people, the United States is the third or fourth largest country by total area, and the third largest by both land area and population. It is one of the world's most ethnically diverse and multicultural nations, the product of large-scale immigration from many countries. The U.S. economy is the world's largest national economy, with an estimated 2011 GDP of $15.1 trillion (22% of nominal global GDP and over 19% of global GDP at purchasing-power parity). Per capita income is the world's sixth-highest.

Grigor Dimitrov (Bulgarian: Григор Димитров; born May 16, 1991, in Haskovo) is a tennis player from Bulgaria. He achieved a career high ranking of World No. 52 on August 22, 2011. Dimitrov also enjoyed a very successful junior career, in which he held the World No. 1 ranking and won the boy's singles titles at the 2008 Wimbledon Championships and the 2008 US Open.

Grigor was born in Haskovo, Bulgaria as the only child of father Dimitar, a tennis coach and mother Maria, a sports teacher and former volleyball player. He first held a tennis racket, given to him by his mother at the age of three and when he was five he began to play daily. During his teenage years he lived in Paris, France while training at Patrick Mouratoglou's Tennis Academy. He speaks fluent Bulgarian and English and says his main interests are all sports, cars, computers and watches.

His first major junior coup was when, at aged 14 he claimed the U14 European title. In 2006 he won the Orange Bowl U16 boys singles and was later named the Eddie Herr International 2007 Rising Star.