atlanta capital and most populous city in the U.S

Prior to the arrival of European Americans in north Georgia, Creek and Cherokee Indians inhabited the area.[10] A Creek village located where Peachtree Creek flows into the Chattahoochee River, Standing Peachtree or Standing Pitch Tree, was the closest Indian settlement to what is now Atlanta.[11] As part of the systematic removal of Native Americans from northern Georgia from 1802 to 1825,the Creek ceded the area that is now Metro Atlanta in 1821.[13] White settlers arrived in 1822, and nearby Decatur was founded the following year.
In 1836, the Georgia General Assembly voted to build the Western and Atlantic Railroad in order to provide a link between the port of Savannah and the Midwest.[15] The initial route was to run from Chattanooga to a spot called simply "Terminus," located east of the Chattahoochee River, which would eventually be linked to the Georgia Railroad from Augusta and the Macon and Western Railroad, which ran from Macon to Savannah. An engineer was chosen to recommend the location of the terminus. Once he surveyed various possible routes, he drove a stake (the “zero milepost”) into the ground in what is now Five Points. A year later, the area around the railroad terminus had developed into a settlement, first known as "Terminus" and then Thrasherville, for John Thrasher, a local merchant who built homes and a general store in the settlement.[16] By 1842, the settlement had six buildings and 30 residents and the town was renamed "Marthasville".[17] The Chief Engineer of the Georgia Railroad, J. Edgar Thomson, suggested renaming the area "Atlantica-Pacifica" to highlight the rail connection westwards, shortened to "Atlanta".[17] The residents approved, and the town was incorporated as Atlanta on December 29, 1847.[18] By 1854, another railroad connected Atlanta to LaGrange, and the town grew to 9,554 by 1860.[19]
During the Civil War, the nexus of multiple railroads in Atlanta made the city a hub for the distribution of military supplies. In 1864, following the capture of Chattanooga, the Union Army moved southward and began its invasion of north Georgia. The region now covered by Metropolitan Atlanta was the location of several major army battles, including Kennesaw Mountain, Peachtree Creek, Jonesborough (now Jonesboro), and the Battle of Atlanta. On September 1, 1864, following a four-month-long siege of the city by the Union Army under the command of General William Tecumseh Sherman, Confederate General John Bell Hood made the decision to retreat from Atlanta. General Hood ordered that all public buildings and possible assets to the Union Army be destroyed. On the next day, Mayor James Calhoun surrendered Atlanta to the Union Army, and on September 7, General Sherman ordered the city's civilian population to evacuate. On November 11, 1864, in preparation of the Union Army's march to Savannah, Sherman ordered for Atlanta to be burned to the ground, sparing only the city's churches and hospitals.[21] After the Civil War ended in 1865, Atlanta was gradually rebuilt. From 1867 until 1888, U.S. Army soldiers occupied the McPherson Barracks in southern Atlanta to ensure that the Reconstruction era reforms were carried out.
According to the United States Census Bureau, the city has a total area of 132.4 square miles (342.9 km2). 131.7 square miles (341.1 km2) of it is land and 0.7 square miles (1.8 km2) of it is water. The total area is 0.54% water. At about 1,050 feet (320 m) above mean sea level the airport is at 1,010 feet (308 m), Atlanta sits atop a ridge south of the Chattahoochee River.
The Eastern Continental Divide line enters Atlanta from the south, proceeding to the downtown area. From downtown, the divide line runs eastward along DeKalb Avenue and the CSX rail lines through Decatur.[37] Rainwater that falls on the south and east side runs eventually into the Atlantic Ocean, while rainwater on the north and west side of the divide runs into the Gulf of Mexico[37] via the Chattahoochee River. That river is part of the ACF River Basin, and from which Atlanta and many of its neighbors draw most of their water. Being at the far northwestern edge of the city, much of the river's natural habitat is still preserved, in part by the Chattahoochee River National Recreation Area. Downstream however, excessive water use during droughts and pollution during floods has been a source of contention and legal battles with neighboring states Alabama and Florida.

Atlanta has a humid subtropical climate, (Cfa) according to the Köppen classification, with hot, humid summers and mild winters that are occasionally cold by the standards of the southern United States. January averages 42.7 °F (5.9 °C), with temperatures in the suburbs slightly cooler. Warm, maritime air can bring springlike highs while strong Arctic air masses can push lows into the teens (−11 to −7 °C). High temperatures in July average 89 °F (31.7 °C) but occasionally exceed 100 °F (38 °C). Atlanta's high mean elevation distinguishes it from most other southern and eastern cities, and contributes to a more temperate climate than is found in areas farther south.
Typical of the southeastern U.S., Atlanta receives abundant rainfall, which is relatively evenly distributed throughout the year, though spring and early fall are markedly drier. Average annual rainfall is 50.2 inches (1,280 mm). Temperatures at or above 90 °F (32 °C) occur more than 40 days per year; overnight freezing can be expected over 45 days, but high temperatures that do not climb above the freezing mark are rare.[41] Snow is not seen every year and averages 2.5 inches (6.4 cm) annually. The heaviest single storm brought around 10 inches (25 cm) on January 23, 1940.[42] True blizzards are rare but possible; one hit in March 1993. Ice storms usually cause more trouble than does snowfall; the most severe such storm may have occurred on January 7, 1973.[43] In 2010, Atlanta had its first white Christmas since 1882.
Extremes range from −9 °F (−23 °C) in February 1899 to 105 °F (41 °C) in July 1980.44] More recently, a low one degree away from the record, was observed on January 21, 1985.
The city's lush tree canopy, which filters out pollutants and cools sidewalks and buildings, has increasingly been under assault from man and nature due to heavy rains, drought, aged forests, new pests, and urban construction. A 2001 study found that Atlanta's heavy tree cover declined from 48% in 1974 to 38% in 1996. This loss of tree canopy resulted in a 33% increase in stormwater runoff and a loss of 11 million pounds of pollutants removed annually, a value of approximately $28 million per year.[60] Due to a historic drought in the late 2000s, Atlanta lost trees at an unprecedented rate. For example, Piedmont Park lost about a dozen large, historic trees in 2009, compared to two or three during normal years. Although many of Atlanta's trees are between 80–100 years old and thus reaching the end of their normal lifespan, the drought accelerated their demise by shrinking the trees' roots. Fortunately, the problem is being addressed by community organizations and city government.[53] Trees Atlanta, a non-profit organization founded in 1985, has planted and distributed over 75,000 shade trees.[61] Atlanta's city government awarded $130,000 in grants to neighborhood groups to plant trees.[53]
Being a city of trees encourages outdoor activity, and thanks to a perpetually mild climate, nature is a constant guest in Atlanta. The city is home to the Atlanta Dogwood Festival, an annual arts and crafts festival held one weekend during early April, when the native dogwoods are in bloom. Downtown's Centennial Olympic Park is the start and finish of the Georgia Marathon, which courses through central Atlanta and Decatur suburbs, business sections and major schools of higher learning like Georgia State University, Agnes Scott College, Emory University and Georgia Tech.