Many of Americas's biggest moments have involved struggles of one kind or another. Here we take a look at four American attractions which have become iconic, due to the history they represent.

National Civil Rights Museum

The Lorraine Hotel, site of the assassination of Dr. Martin Luther King, Jr. in 1964 during the Memphis sanitation workers' strike, serves as the focal point of this museum. A moving tribute captures the history and hardship of the civil rights movement, and examines the continuing struggle for civil rights across the globe, through emotionally compelling, interactive exhibits.

Outside, on the balcony where King was shot, a white wreath marks the tragedy. Across the street, at the boarding house where James Earl Ray fired the fatal shot, exhibits examine whether there was a conspiracy or Ray acted alone. The museum also offers profiles of those who have been honored with its Freedom Awards, including Oprah Winfrey, President Bill Clinton, Lech Walesa, the Dalai Lama, and others.

The Alamo

"Remember the Alamo!" This iconic phrase is imbedded in American culture, often as a cry to buck up against overwhelming odds. The most visited tourist attraction in Texas is just a few blocks from the famous San Antonio Riverwalk, and is surrounded today by souvenir shops and other tourist-oriented businesses.

But the Alamo was the site of a March 1836 battle between Mexican forces led by Santa Anna, and Texas revolutionaries including Davy Crockett and Jim Bowie. Texas was fighting to break away from Mexico, and had just, the year before, routed Mexican troops holding San Antonio. They established headquarters at a 5-acre site and its main building, a former Spanish mission.

Seeking to recapture lost Mexican territory, Santa Anna led 1,500 troops against the 185 Texans holding the mission and grounds. Despite the odds, the Texans were credited with a heroic defense that resulted in all of their deaths, and the deaths of 600 Mexican soldiers. That some survivors were executed outraged other Texans, who shouted the rallying cry a month later at the Battle of San Jacinto (in which Texans defeated the Mexican Army and secured independence for Texas as a sovereign nation until it joined the United States in 1845).

Today, the five-acre Alamo site, with its gardens and mission, is treated as hallowed ground by both Americans and Mexicans. It's particularly breathtaking at night, a surprise to many who happen upon it then.

Pearl Harbor

They're called "tears of a soldier," the black drops of oil that bubble to the surface

from the USS Arizona sunken beneath blue Hawaiian waters of Oahu. For visitors gazing down from the Memorial straddling the ship, the black tears create an eerie sense of the lost men below.

Pearl Harbor was home to the U.S. Pacific Fleet, amassed at Pearl Harbor but not at war. Japan's surprise attack December 7, 1941 devastated the U.S. ships stationed there, propelling the U.S. into World War II.

For the 4,500 daily visitors to this far-flung but oh-so-important American memorial, the blue water sparkles and tropical air is balmy, just like the infamous day of 72 years ago. But the sight of the ship beneath the clear water - and horrific tales of burning ships, downed planes and rescue attempts brings sobering thoughts to a spectacular setting.

9/11 Memorial

At the site of the newly opened 9/11 Memorial in lower Manhattan, there are two large, dark reflecting pools, each nearly an acre in size, and with water sheeting down its interior walls. Each of these massive water features, dark and seemingly bottomless, represents a World Trade Center tower.

Names of the nearly 3,000 who died in the September 11, 2001, attacks on New York are engraved around the pools' edges. Visitors gently touch the letters--names of friends, family, fellow Americans, visiting foreigners, first responders--all lost in the Twin Tower attacks. Names continue-- those lost on the four planes. Those lost at the Pentagon, and the victims of the 1993 World Trade Center bombing. The Memorial's name is "Reflecting Absence."

The 16-acre site is filled with hundreds of trees. Among them is a pear tree called "The Survivor's Tree." Healthy, green and thriving today, it had been badly burned, with but a single branch still alive after the World Trade Center attack 12 years ago.

Vote for your favorite iconic American attraction at 10best.com/awards/travel. Voting ends September 9 at noon ET.

10BEST.COM: More about the 2013 Readers' Choice Awards

Read or Share this story: http://usat.ly/1fFLItn