We couldn't possibly carry out most of the activities in our life, without depending on science and technology. Although African-Americans in many parts of the world were denied proper education for a long time, there have been several researchers and scientists who have made their mark in fields of science, technology and medicine. Here is brief information on some of the most popular scientists whose contributions have changed the world. Popular African-American Scientists Benjamin Banneker (1731-1806) Similar to most of the other African-American scientists of the time, Benjamin Banneker was self-taught. But, what is more interesting is that although being a man of limited means, Banneker was one of the most famous scientists, mathematician and author. He modeled a wooden clock that worked successfully for 50 years; wrote a series of almanacs; and could rightly predict eclipses. Banneker corresponded with Thomas Jefferson on issues like racial discrimination and justice to African-American. Daniel Hale Williams (1858-1931) Daniel Hale Williams was the first African-American cardiologist, who is also credited for being one of the first surgeons to perform the open-heart surgery in the United States of America. His work is considered outstanding because of the fact that the patient recovered completely within 51 days and lived for another 50 years. Williams opened the first non-segregated hospital (having an interracial staff) in America. Dr. Williams was appointed surgeon-in-chief of Freedman's Hospital, and also co-founded the National Medical Association. George Washington Carver (1864-1943) Although born in slavery, George Washington Carver made his mark in the fields of agriculture, botany and education. He is the pioneer for developing more than hundred applications of peanuts, soy and sweet potatoes. He taught poor farmers different methods like crop rotation so as to grow alternative crops. Among his numerous inventions, only a few are patented. Although Carver was one of the most celebrated scientists of USA, he lived a simple life and devoted it entirely for the benefit of others. Garrett Morgan (1877-1963) Although not recognized and credited for his inventions and contributions earlier, Garrett Morgan continued carrying out his experiments to develop simple products for helping people in their day-to-day life. Traffic signal, a hair-straightening product, a respiratory device (mask), and a modified sewing machine are some of his most notable inventions. The invention of the traffic signal is controversial as there are very few records claiming Morgan's work and its actual usage. Unfortunately, Garrett Morgan's extraordinary work was recognized very late in his life. Elijah McCoy (1844 - 1929) Elijah McCoy is another African-American scientist with a large number of patents to his credit. He received 57 patents, mostly related to steam engines. However, his most popular invention is the automatic lubricator, used to lubricate engines of steam ships and locomotives. He also formed the Elijah McCoy Manufacturing Company. Interestingly, the phrase 'The real McCoy' is believed to be associated with McCoy's invention. Granville Woods (1856-1910) Granville Woods is known for his extensive work in the field of railroad industry. He invented a machine known as telegraphony, a combination of the telephone and telegraph. He invented the Multiplex Telegraph, the automatic brake; and also made improvement to existing inventions like telephone, telegraph, phonograph, etc. Granville Woods has more than 50 patents to his credit; and is often termed as the 'Black Edison'. Lewis Howard Latimer (1848-1928) Lewis Latimer is well-known for inventing a method to make improved carbon filaments, used in light bulbs. This method helped in increasing the life of bulbs, and also made them less expensive. Latimer received patents for inventing a 'Process of Manufacturing Carbons' and for 'Water Closet for Railroad Cars'. In his later life, he worked as a patent consultant to law firms. Interestingly, Lewis Latimer worked with two of the greatest scientists of his time, Thomas Edison and Alexander Graham Bell. Percy Julian (1899-1975) Percy Lavon Julian is popular for several reasons. He was one of the first African-Americans to be awarded a doctorate in chemistry. He received nearly 130 chemical patents. Percy Julian first synthesized physostigmine, a drug used for treating glaucoma and Alzheimer's disease. Julian's contribution laid the foundation for producing cortisone, other steroids and birth control pills. He was the first African-American chemist elected to the National Academy of the Sciences. Sarah E. Goode (ca. 1850-1905) Among female scientists, Sarah E. Goode is the most popular one as she is the first African-American woman to receive a patent in the U.S. Her invention of the folding or the cabinet bed has been one of the most useful and practical inventions. Although born a slave, Goode became free after the Civil War, and owned a furniture store. The cabinet bed was created more out of necessity as her customers complained of having smaller houses and lack of space to store goods. Patricia Bath (1942) Dr. Patricia Bath is the first woman to be appointed to the faculty of Jules Stein Eye Institute; is the first African-American to serve as a surgeon at the UCLA Medical Center; and also is the first African-American to receive a patent in the field of medicine. Her remarkable invention of Laserphaco Probe is used to treat cataract in many parts of the world. Dr. Bath has 4 patents to her credit, and has worked tirelessly for complete treatment of blindness. James Edward Maceo West (1931) James West's invention, the foil electret microphone, finds its applicability in nearly all the telephones and audio recording devices in the world. While working in Bell Laboratory, James West and Gerhard Sessler developed the electret microphone, which is now widely used for its reliability, high performance, small size and accuracy. West has, astonishingly, over 200 U.S and foreign patents to his credit. He is inducted to the National Inventors Hall of Fame. Emmett Chappelle (1925) Emmett Chappelle is one of the most distinguished African-American scientists of the 20th century. He has made notable contributions in the field of food production, chemistry and medicine. He discovered that, due to certain chemical combinations, all living organisms can emit light. He also developed techniques to determine health of plants; to detect presence of bacteria in food, drinking water, etc. Chappelle has received 14 U.S patents. Other Notable African-American Scientists and Inventors Apart from the aforementioned, here is a list of African-American inventors / scientists whose works are equally noteworthy. The list is in an alphabetical order.

• Charles R. Drew - Developing blood bank
• Charles Henry Turner - Proved that insects can hear
• Ernest Everett Just - Role of Cell Surface
• Jan Ernst Matzeliger - Shoe Lasting (shaping) Machine
• Marie Van Brittan Brown - Home Security System
• Mae Jemison - First African-American woman to travel to space
• Mark Dean - One-gigahertz Computer Processor Chip, and a color PC monitor
• Marie Maynard Daly - First African-American woman awarded a doctorate in chemistry.
• Marjorie Stewart Joyner - Permanent Wave Design
• Norbert Rillieux - Multiple-effect Evaporator
• Otis Boykin - Resistor, and a control unit for the heart pacemaker
• Sarah Boone - Improved Ironing Board

These scientists played an important role in helping in advancement of science, technology, medicine, etc. There were several others whose contributions were not recorded. However, the common thread between all of them was that they worked tirelessly for the betterment of the society.