Origin

When and Where Easter Origionated
Easter was established as a holiday in 30 A.D. as a Christian celebration of Jesus Christ's resurrection, the earliest recorded observation was in the 2nd Century but was not celebrated by Americans until the Civil War. The Holiday is celebrated on the first Sunday after the first full moon on or after the spring equinox. Easter became a Christian holiday in the early Christian church. It was debated for a while by early Christians whether Easter should be celebrated on Nisan 14 (Passover) or the following Sunday.
sources: World History EDU and Britanica and WTSP

Origional Customs
It was common that Christians would place lamb meat under the altar and ate it on Easter, after it had been blessed. Lenten fast has ended on Easter since the 12th century and is celebrated with big meals of ham, eggs, cheese, bread, and sweets. The egg is a big symbol of life and rebirth, in early Mesopotamia, Christians would dye eggs red to resemble Christ's blood. Feaasteing, dancing, and the exchange of eggs in Europe are all ways Christians used to celebrate new life and rebirth.
sources: World History EDU and Britanica

Origional Purpose
Easter's origional purpose was to celebrate the resurection of Jesus Christ from the dead. The holiday's purpose has not changed but to many, it is also commonly associated with changing of the seasons and signifies that Spring is coming. Origins of the holiday has also been traced back to ancient pagan celebrations of the vernal equinox.
sources: World History EDU and Britanica and WTSP