Short answers, pulled from the story.
The name originated in 1650 when magistrate Gervase Bennet applied it to George Fox after Fox told him and fellow magistrate Nathaniel Barton to tremble at the word of the Lord. The term began as a taunt but was eventually accepted by many Friends themselves.
Quaker worship ranges from completely silent unprogrammed meetings, where any member may speak if moved by the spirit, to fully programmed evangelical services with hymns, sermons, and a pastor. Around 11% of Quakers worldwide practice unprogrammed silent worship; around 89% practice some form of programmed or semi-programmed worship.
Quakerism arose in mid-17th-century England. George Fox claimed a founding revelation in 1647 while living in Mansfield, Nottinghamshire, and had a vision on Pendle Hill in Lancashire in 1652 that drove him to travel and preach. The movement grew out of dissenting Protestant groups that emerged during and after the English Civil War of 1642-1651.
Nine of the twelve founding members of the Society for Effecting the Abolition of the Slave Trade were Quakers. Five of those nine had been part of an informal group that presented the first parliamentary petition against the slave trade to Parliament in 1783. In the 19th century, Levi Coffin, Isaac Hopper, and Laura Smith Haviland were prominent Quaker figures in the Underground Railroad.
Quakers founded Barclays and Lloyds in banking, Cadbury, Fry's, and Rowntree in chocolate and confectionery, Clarks in footwear, Huntley & Palmers in biscuits, and Allen & Hanburys in pharmaceuticals. Edward Pease promoted the Stockton and Darlington Railway, the world's first public steam-powered railway. Quakers also helped establish Oxfam and Greenpeace.
In 2017, there were an estimated 377,557 adult Quakers worldwide. Around 49% lived in Africa, making it the continent with the largest Quaker population, followed by 22% in North America. Kenya alone had 119,200 Quakers in 2017.