During the process, rocks, minerals and other parent materials are weathered. The resulting soil varies depending on the degree of weathering (a function of climate), the duration of weathering (a function of time), the site-specific biological activity, and landscape position (a function of topography).

To put the formation of soil into perspective, think about some of the things that have occurred during the time it takes to one inch of soil to form:

• New planets that could sustain life are discovered orbiting a neighborhood star-1996
• Americans with Disabilities Act becomes law-1990
• The Berlin Wall is torn down, signaling an end to the Cold War-1989
• Viking I becomes the first spaceship to reach Mars-1976
• U.S. Armed Forces withdraw from Vietnam-1975 Congress passes Endangered Species Act-1973
• Richard Leakey discovers hominid skull, 2.6 million years old in northern Kenya-1972
• First "Earth Day" is observed-1970
• American astronaut Neil Armstrong walks on the moon-1969
• Thurgood Marshall becomes first African American member of U.S. supreme court-1967
• Rev. Martin Luther King, Jr. receives the Nobel Peace Prize in Oslo, Norway-1964
• President John F. Kennedy is assassinated in Dallas, Texas-1963
• British pop group The Beatles make their first recordings-1962
• Soviet cosmonaut Yuri Gagarin becomes first human to orbit Earth-1961
• African American trackstar Wilma Rudolph wins three gold metals at the Rome Olympic Games-1960
• Elvis Presley records "Heartbreak Hotel"-1956
• English runner Robert Bannister runs mile in under 4 minutes-1954
• Korean War ends-1953
• Dr. Jonas Salk successfully tests polio vaccine-1952
• Ten million homes have television receivers-1951
• Mao Tse-Tung rises to power in China-1949
• The transistor is invented in Bell Laboratories in the U.S.-1948
• ENIAC, the first successful electronic digital computer, becomes operational-1946
• World War II ends-1945
• Oswald Avery determines that DNA is the hereditary material of the cell-1944
• Prehistoric cave paintings are discovered at Lascaux, France-1940
• Child film actress Judy Garland stars in "The Wizard of Oz"-1939
• A Coelacanth, a fish thought extinct for 65 million years, is caught of the coast of Africa-1938
• First local conservation district is created-1937
• Drought leads to severe dust storms in "Dust Bowl" region of Great Plains-1934
• Frances Perkins, Secretary of Labor, becomes first woman in U.S. cabinet-1933
• Charles Curtis of the Kaw Tribe in Kansas, a U.S. senator for 25 years, becomes Vice President of the United States-1929
• Dr. H.O. Sargent and Dr. George Washington Owens establish the New Farmers of America-1927
• Hirohito becomes 124th Emperor of Japan-1926
• 19th amendment to the U.S. Constitution gives women the right tovote-1920
• World War I ends- 1918
• Russian Revolution begins -1917
• Jeanette Rankin (R-Montana) elected first U.S. Congresswoman-1916
• Albert Einstein formulates his general theory of relativity-1915
• Jim Thorpe of the Sauk and Fox Tribes wins Decathlon and Pentathlon in Olympic Games, Sweden-1912
• First Model "T" Ford rolls off assembly line-1908
• Upton Sinclair's novel, "The Jungle," leads to U.S. Pure Food and Drug Act-1906
• Orville Wright makes first successful flight in self-propelled airplane-1903
• Gugliemo Marconi tests radio transmissions between England and Newfoundland-1901
• Britain obtains 99-year lease for Hong Kong from China-1898
• Dr. George Washington Carver begins to develop over 300 products from the peanut and 118 from the sweet potato-1896
• German Physicist Wilhelm C. Roentgen discovers X-rays-1895
• San Francisco Examiner begins printing first newspaper comic strip-1892
• Thomas Edison invents phonograph -1877
• Alexander Graham Bell invents telephone-1875
• U.S. experiences worst grasshopper plague in its history-1874
• Congress founds first national park, Yellowstone-1872
• British-American explorer Henry Morton Stanley finds Dr. David Livingstone in Central Africa-1871
• Suez Canal opens- 1869
• U.S. Civil War ends and 13th Amendment to the U.S. Constitution abolishes slavery-1865
• President Abraham Lincoln delivers Gettysburg Address-1863
• Congress passes the Homestead Act-1862
• Gregor Mendel begins formal experiments in genetics-1856
• American writer and naturalist Henry David Thoreau publishes "Walden"-1854
• Frederick Douglass establishes the abolitionist newspaper, "The North Star"-1847
• Samuel F.B. Morse develops code for electric telegraph system-1838
• Texas proclaims independence from Mexico-1836
• Louis Braille publishes system of writing for the blind-1829
• President James Monroe formulates doctrine of U.S. policy opposing outside interference in the Americas-1923
• Emma Hart Willard founds first U.S. women's college, Troy Female Seminary, in Troy, New York-1821
• Construction of Erie Canal begins-1817
• Grimm's Fairy Tales are published in Germany-1812
• Kamehameha I becomes ruler of Hawaii and establishes Kamehameha dynasty-1810
• Ludwig van Beethoven premieres Fifth and Sixth Symphonies-1808
• Lewis and Clark begin expedition to the American Northwest-1804
• A 33,000-year-old frozen mammoth is discovered at Russia's Lena River-1799
• English physician Edward Jenner develops vaccination against smallpox-1796
• Eli Whitney invents cotton gin-1793
• Mary Wollstonecraft publishes "A Vindication of the Rights of Women"-1792
• Bill of Rights is ratified-1791
• French Revolution begins with an attack on the Bastille-1789
• The U.S. Constitution is ratified-1788
• Mozart's "The Marriage of Figaro" premieres-1786
• American Revolutionary War ends-1781
• Continental Congress adopts Declaration of Independence -1776
• American Colonists throw British tea into Boston Harbor-1773
• Crispic Attucks becomes the first person and African American to die in the Revolutionary War in the "Boston Massacre"-1770
• French and Indian War ends -1763
• Thomas Jefferson is born-1743
• George Frederick Handel composes "Messiah"-1741
• British agriculturist Jethro Tull invents seed drill-1733
• George Washington is born-1732
• First permanent Native American school is created in Williamsburg, Virginia-1720
• Population of New York City reaches 7,000-1720
• Italian musician Bartolommeo Cristofori invents the piano-1709
• Benjamin Franklin is born-1706
• Russian tzar, Peter the Great, imposes tax on beards-1698
• First public school is established in America-1689
• Rice cultivation begins in North America-1685
• Edmund Halley observes Great Comet, which is later named for him-1682
• The Dodo, a large flightless bird, becomes extinct-1681
• First mail service in North America is John Elliot's translation into Algonquian-1661
• First Quakers land in America-1657
• First book is printed in Native American language-1653
• Cardinal Richelieu founds L'Academie Francaise in Paris-1635
• First newspaper, Gazette de France, is published in Paris-1631
• Peter Minuit founds Dutch Colony of New Amsterdam (now New York)-1625
• Pilgrim leaders at Plymouth Colony establish a governing authority through Mayflower Compact-1620
• Native American princess Pocahontas marries John Rolf-1614
• Spanish found Santa Fe (New Mexico)-1609
• Native Americans teach colonists how to raise corn-1608
• John Smith founds first permanent English colony in North America at Jamestown, Virginia-1607
• Spain founds colony in St. Augustine, Florida-1565
• Shakespeare and Galileo are born-1564
• An earthquake in China is worst in history with a death toll of 830,000-1556
• University of Mexico is founded-1551
• First botanical garden is founded in Pisa, Italy-1543 Francesco Coronado introduces horses to North America-1540
• The Reformation begins-1517
• Juan Ponce de Leon discovers Florida-1513
• Michelangelo finishes painting Sistine Chapel ceiling-1512
• First sugar cane mill is established in the Americas-1509
• Leonardo da Vinci completes "Mona Lisa"-1505
• The Incan Empire reaches its height-1500
• The toothbrush is invented by a Chinese dentist-1498
• John Cabot discovers Newfoundland -1497

Courtesy of: The USDA, Natural Resources Conservation Service