Jefferson and Burr received the same
number of electoral votes. The House of
Representatives eventually chose Jefferson
as the winner.
The most important event of Jefferson’s
first term was the purchase of a large
area of land known as the Louisiana
Territory from France in 1803. The territory
doubled the size of the United
States. The president launched the Lewis
and Clark Expedition to explore the new
territory. Jefferson easily won reelection
in 1804, but his second term was less
successful than the first. A war between
Britain and France hurt U.S. trade with
Europe.
Retirement
In 1809 Jefferson retired to Monticello,
where he wrote, looked after his estate,
and entertained friends. His last great
project was founding the University of
Virginia at Charlottesville. Jefferson died
on July 4, 1826.
#More to explore
Adams, John • American Revolution
• Declaration of Independence
• Democracy • Hamilton, Alexander
• Lewis and Clark Expedition
• Louisiana Purchase • Slavery • United
States
April 13, July 4,
1743 1776 1796 1800 1803 1809 1826
Jefferson is
born in
Shadwell,
Virginia.
Jefferson
writes the
Declaration of
Independence.
Jefferson is
elected vice
president under
President John
Adams.
Jefferson is
elected
president.
The Louisiana
Purchase
doubles the
size of the
United States.
Jefferson retires
after a second
term.
Jefferson
dies at his
home near
Charlottesville,
Virginia.
T I M E L I N E
18 Jefferson, Thomas BRITANNICA STUDENT ENCYCLOPEDIA
Jefferson City
Population
(2000 census)
39,636; (2007
estimate)
40,564
Jefferson City is the capital of the U.S.
state of Missouri. The city is located on
the Missouri River.
Farmers from the surrounding area sell
crops and livestock in Jefferson City.
Many people in the city work for the
government or in health care or education.
Factories in Jefferson City make
shoes, books, electrical appliances, and
food products.
The city began as a small settlement
called Lohman’s Landing. In 1821 the
settlement was selected as the site for the
capital of Missouri. A son of the famous
American pioneer Daniel Boone laid out
the city in 1822. It was named after
Thomas Jefferson, the third president of
the United States. Jefferson City officially
became the state capital in 1826.
..More to explore
Missouri • Missouri River
Jellyfish
Jellyfish are sea animals with a soft, jellylike
body and no bones. They have tentacles,
or feelers, that they use to sting
their prey. Sometimes they sting swimming
people, too.
Jellyfish are related to corals and sea
anemones. There are about 200 species,
or types, of jellyfish. They are found in
all oceans. Most live at or near the surface
of the water.
A typical jellyfish is shaped like a bell or
an umbrella. Some jellyfish are hardly
large enough to be seen. Others are
more than 6 feet (2 meters) across. Jellyfish
can be transparent (see-through),
white, brown, pink, blue, or maroon.
Some jellyfish have eyes around the edge
of the body. The mouth and stomach are
in the middle of the body.
A jellyfish may have a few or many tentacles.
Thin tentacles run around the
edge of the body. Four or more larger
tentacles hang down from the middle of
the body, below the mouth. The tentacles
are lined with stinging cells that
make poison. The poison can stun small
animals. The tentacles then pull the animals
into the mouth.
Tourists leave the Governor’s Mansion in
Jefferson City, Missouri.
Jellyfish are
not fish. They
are a much
simpler form
of living thing.
BRITANNICA STUDENT ENCYCLOPEDIA Jellyfish 19
Certain jellyfish can be very dangerous
to humans. Even a small sting from the
jellyfish called sea wasps can kill a person
within a few minutes.
#More to explore
Coral • Sea Anemone
Jemison, Mae
Mae Jemison was the first African
American woman to become an astronaut.
She was a part of the crew of the
space shuttle Endeavor, which orbited
Earth for more than a week in 1992.
Jemison was born on October 17, 1956,
in Decatur, Alabama. She was the
youngest of three children. When she
was 3, the family moved to Chicago,
Illinois. Even as a young girl Jemison
was deeply interested in science.
Jemison graduated from high school at
age 16. She then received a scholarship
to attend Stanford University in California.
She graduated from there in 1977
with a degree in chemical engineering.
After Stanford, Jemison attended medical
school at Cornell University in New
York. She received her medical degree in
1981. She worked as a doctor first in
Los Angeles, California, and then with
the Peace Corps inWest Africa.
Then Jemison applied to the National
Aeronautics and Space Administration
(NASA) to become an astronaut. She
was one of only 15 out of 2,000 applicants
accepted by NASA. Jemison
entered NASA’s astronaut program in
1987. In 1992 Jemison flew aboard the
shuttle Endeavor as the science mission
specialist. At the time she was the only
female African American astronaut.
After retiring from NASA in 1993,
Jemison founded her own company, the
Jemison Group. The company created
new technologies, especially to help
developing countries. Jemison also cre-
Jellyfish swim by opening and closing their
bodies like an umbrella.
