Introduction to American Philanthropists.
No.1: Bill and Melinda Gates
Amount donated in 2014: $1.5-billion
Beneficiary: Bill & Melinda Gates Foundation
Background: Mr. Gates is a co-founder of Microsoft, in Redmond, Wash., and they both are co-chairmen of the foundation they established in 2000.
No.2: Ralph Wilson Jnr
Amount donated in 2014: Approximately $1-billion
Beneficiary: Ralph C. Wilson Jr. Foundation
Background: Mr. Wilson founded the Buffalo Bills football team in 1959 and his estate sold the franchise in 2014 for $1.4-billion.
No.3: Ted Stanley
Amount donated in 2014: an estimated $652.4-million
Top beneficiary: Broad Institute
Background: Mr. Stanley founded MBI, a company that develops and markets collectible items.
No.4: Jan Koum
Amount donated in 2014: $556-million
Jan Koum was a teenager living in Fastiv, Ukraine, when the Soviet Union fell in 1991. He had little to his name when he left for the United States a year later.
No.5: Sean Parker
Amount donated in 2014: $550-million
Better known as the guy who helped start Napster and the founding president of Facebook
Taking the No. 5 spot on the Philanthropy 50 list, Mr. Parker gave a total of $550-million last year to the Sean N. Parker Foundation
No.6: Nicholas and Jill Woodman
Amount donated in 2014: $500-million
Beneficiary: Silicon Valley Community Foundation
Background: The Woodmans founded GoPro, a company that creates high-definition cameras.
No.7: Michael Bloomberg
Amount donated in 2014: $462-million
Beneficiaries: Arts, education, environmental, and public-health groups and programs aimed at improving city governments around the world.
No.8: Rachel Lambert (Bunny) Mellon
Amount donated in 2014: Approximately $411.3-million
Her friends say she was happiest working in the garden, but the heiress Bunny Mellon was no backyard dabbler. She was a self-taught and respected horticulturalist who from childhood had studied plant and gardening design.
No.9: Sergey Brin
Amount donated in 2014: $382.8-million
Beneficiary: Brin Wojcicki Foundation
Background: Mr. Brin co-founded Google.
No.10: Paul Allen
Amount donated in 2014: $298-million
Top beneficiary: Paul G. Allen Family Foundation
Other notable gift: Allen Institute for Cell Science
No.11: Leonard Blavatnik
The Ukraine-born American citizen with an estimated net worth of $18.5 billion does however prefer living in London.
Last year he gave £59 million (about $90 million) to charitable causes, according to the Sunday Times Giving List 2015.