1. 1859
   1919
2. 1959
   1979

The U.S. gained not only its 50th​ but also its 49th state in 1959 with the addition of Alaska and Hawaii. Alaska came first, in January, followed by Hawaii in August.

1. "M*A*S*H*"
   "The Golden Girls"
2. "The Brady Bunch"
   "Father Knows Best"

Betty White starred as Rose Nylund on "The Golden Girls," which ran from 1985 to 1992. The series featured White, Bea Arthur, Rue McClanahan and Esetelle Getty enjoying their golden years as a makeshift family.

1. Albert Einstein
   Louis Pasteur
2. Marie Curie
   Alexander Graham Bell

It was Einstein who developed this famous formula, known as the mass-energy equilibrium. He also developed the theory of relativity, earning him the Nobel Prize in Physics in 1921.

1. 1939
   1969
2. 1989
   2009

Armstrong walked on the moon in July 1969. He was part of the Apollo 11 mission, with fellow astronauts Buzz Aldrin and Michael Collins.

1. Bart
   Lisa
2. Maggie
   Nelson

"The Simpsons" premiered in 1989 and launched its 30th season in 2018. This beloved series focuses on Marge and Homer Simpson, who are parents to three children named Bart, Lisa, ​and Maggie.

1. Telephone
   Television
2. Printing press
   Telescope

In the 1400s, German Johannes Gutenberg developed movable type, leading to a successful printing press. His invention made widespread literacy possible, and helped spur everything from the Renaissance to the Scientific Revolution.

1. Colonists
   Confederacy
2. Union
   Apache

The south became known as the Confederacy as they took on the northern Union states during the American Civil War. The bloody event ended in 1865 when Lee surrendered to Grant at Appomattox Court House in Virginia.

1. 1999
   2004
2. 2009
   2014

Barrack Obama became the 44th President -- and the first African-American to hold the office on January 20, 2009. Before becoming president, he was a lawyer and a s​enator representing Illinois.

1. "The Great Gatsby"
   "The Grapes of Wrath"
2. "To Kill a Mockingbird"
   "Moby Dick"

"To Kill a Mockingbird" earned Harper Lee a Pulitzer Prize after it was published in 1960. Her novel of racial tensions in the 1930s south featured a narrator named Jean Finch -- also known as Scout.

1. Gu
   Gd
2. Au
   Tn

Gold, which has atomic number 79, is represented by the symbol Au. Its shimmery metal cousin, silver, has a similar symbol -- Ag.

1. Vietnam
   Korea
2. WWI
   WWII

World War II endured from 1939 to 1945. While many countries were involved, the U.S. remained largely unaffected until a disastrous bombing of a U.S. military base at Pearl Harbor, Hawaii, in 1941.

1. 1945
   1965
2. 1985
   2005

The iconic American muscle car, the Ford Mustang, came out in mid-1965. Purists call the earliest models the "64-1/2" because it came out earlier than the typical auto release for the year.

1. 4
   6
2. 8
   12

A cup consists of 8 liquid ounces. There are 2 cups in a pint, and 8 pints per gallon. Knowing these quick measurement swaps is useful for everything from baking to counting calories.

1. His mom
   Kristin
2. Dusty
   Vaughn

A major cliffhanger in season three of the show, "Dallas," left fans wondering who shot J.R. Ewing, played by Larry Hagman. After an unbearable off-season, fans learned it was J.R.'s own sister-in-law who pulled the trigger.

1. WWI
   WWII
2. War of 1812
   Civil War

The assasination of Austria's Archduke Franz Ferdinand in 1914 was a key event that helped to set off WWI. The war pitted the Allies, which included France, England, Russia, the U.S. and Japan, against the Axis powers of Germany, Austria and the Ottoman Empire.

1. London
   Manchester
2. Liverpool
   Oxford

The Fab Four hailed from Liverpool, a working-class city in northern England. Fans can still visit Liverpool today and see places like Strawberry Fields or Penny Lane.

1. 1991
   2001
2. 2008
   2014

September 11, 2001, is a day that will forever be remembered in the U.S. On that day, a terrorist attack by al-Qaeda claimed almost 3,000 lives.

1. "Black or White"
   "Thriller"
2. "Beat It"
   "Billie Jean"

Michael Jackson's "Thriller" album was the best-selling album of 1983, and one of the best-selling albums of all time. In addition to the title track, it featured hits like "Beat it" and "Billie Jean" -- but "Black or White" appeared on a different album.

1. 1.0
   2.54
2. 4.25
   7.11

Metric or imperial? It doesn't matter if you know some basic rules of switching from one to another. For instance, an inch is equal to 2.54 centimeters, and there are 30.48 centimeters in one foot.

1. Harper Lee
   Jane Austen
2. Mark Twain
   Charlotte Bronte

English writer Charlotte Bronte created the masterful classic, "Jane Eyre." Her sister Emily is famous for writing another classic novel, "Wuthering Heights."

1. 12th
   19th
2. 21st
   26th

Just 100 years ago, women didn't have the right to elect their leaders. That all changed with the 19th amendment, which gave women in the U.S. the right to vote.

1. Sydney
   Melbourne
2. Canberra
   Perth

The capital of Australia is probably not a city you're all that familiar with. The city of Canberra, home to 410,000 people, is located about 170 miles south of Sydney and is home to the nation's administrative headquarters.

1. 106
   156
2. 206
   306

Humans are born with 270 bones, which fuses to 206 by adulthood. About half of these bones are located in the hands and feet.

1. Free the slaves
   End the Civil War
2. Make Lincoln the president
   Declare Christianity as the official U.S. religion

In January 1863, President Abraham Lincoln issued his iconic Emancipation Proclamation. This order freed the slaves, granting more than 3.5 million people a whole new life.

1. New York
   Paris
2. London
   Tokyo

At 1,063 feet tall, the Eiffel Tower soars high above the city of Paris, France. Made from iron, it was erected in 1889 to serve as the entrance to the World's Fair.

1. Iraq
   Egypt
2. Russia
   Mexico

The Sumerian people developed the first written language, known as cuneiform, around 2600 BC. They lived in Mesopotamia, which is now known as Iraq.

1. 1689
   1739
2. 1789
   1889

George Washington served as a General in the American Revolutionary War. He was elected the first President of the U.S. in 1789, a title he held until 1797.

1. Mammalia
   Plantae
2. Fungi
   Animalia

Biologists divide all living things into five Kingdoms. These include Prokaryotae, Protoctista, Fungi, Plantae and Animalia.

1. Florida
   Pennsylvania
2. Montana
   New Jersey

Four planes were hijacked during the terrorist attack of September 11, 2001. Two were flown into the World Trade Center, one flew into the Pentagon, and the fourth crashed into a field in Pennsylvania.

1. Atlanta
   Boston
2. Charlotte
   Dallas

John Pemberton invented Coca-Cola in his Atlanta pharmacy in 1886. Rival Pepsi began in New Bern, North Carolina, in 1893.

1. Washington
   Lincoln
2. Taft
   Jefferson

Completed in 1941, Mt. Rushmore National Monument is carved into the Black Hills of South Dakota. It's adorned with the faces of four Presidents: Washington, Lincoln, Jefferson and Roosevelt.

1. Elizabeth Taylor
   Vivian Leigh
2. Shirley Temple
   Judy Garland

A young Judy Garland starred as Dorothy in the 1939 film, "The Wizard of Oz." The film, based on the classic L. Frank Baum novel, has been remade many times since on film and stage.

1. Computer
   Polio vaccine
2. Pasteurization
   Pagers

In 1954, Jonas Salk put his polio vaccine to the test, injecting it into millions. It was a huge success, and saved thousands of children from the horrific paralysis and death associated with the disease.

1. Ancient Greek
   Latin
2. Cuneiform
   Hieroglyphics

The Rosetta Stone was a seemingly banal document discovered in 1799. Because it contained the same information carved in three separate languages, it allowed archaeologists to decipher Egyptian hieroglyphics for the first time.

1. 2,600 BC
   1,300 BC
2. 30 BC
   600 AD

Though she's seen as an ancient figure, Cleopatra lived from 69 to 30 BC. That means she lived closer to your own life than she did to the time that the Great Pyramid was constructed.

1. Ottawa
   Montreal
2. Vancouver
   Toronto

Though it's much smaller than Toronto, Ottawa in southern Ontario serves as Canada's capital city. Founded as Bytown in the 1820s, it was established as the capital in 1826.

1. Greg
   Marsha
2. Ginger
   Peter

"The Brady Bunch" was a happy-go-lucky family series that aired in the '70s. It told the story of a man named Brady, his lovely wife, Carol, and their six children: Greg, Marsha, Jan, Peter, Bobby and Cindy.

1. F. Scott Fitzgerald
   Herman Melville
2. Mark Twain
   John Steinbeck

F. Scott Fitzgerald released "The Great Gatsby" in 1925. This decadent tale of the '20s tells the story of a man named Jay Gatsby and the girl he will never win.

1. France
   England
2. Russia
   Mexico

The American Revolution was a war between British colonists in the New World and the soldiers of Great Britain. It lasted from 1765 to 1783, when the colonists won their independence.

1. 20
   26
2. 32
   46

Kids are born with 20 teeth, while a typical adult has 32. This includes the wisdom teeth, or third molars, which many people have removed these days.