Related by context. Frequent words. (Click for all words.) 52 Abraham Lincoln 52 explorers 52 Sacagawea 48 Ulysses S. Grant 48 bicentennial 48 Nez Perce 48 Civil War 47 expedition 47 Theodore Roosevelt 46 steamboat 46 Revolutionary War 44 Sitting Bull 44 Quincy Adams 44 Confederate 44 re enactors 43 Teddy Roosevelt 43 colonists 43 Davy Crockett 43 Expedition 42 Native Americans 42 Napoleon Bonaparte 42 David Thoreau 41 Franklin D. Roosevelt 41 Abigail Adams 41 Emancipation Proclamation 41 Franklin Roosevelt 41 Mark Twain 41 Thoreau 41 Pony Express 40 John Wilkes Booth 40 Twain 40 Benjamin Franklin 40 Dwight D. Eisenhower 40 Abe Lincoln 40 Dwight Eisenhower 40 Amelia Earhart 40 Pocahontas 40 Confederates 40 ancestor 40 upriver 40 Franklin Delano Roosevelt 40 Indian tribes 39 Charles Darwin 39 riverboat 39 Harry Truman 39 freed slaves 39 Ralph Waldo Emerson 39 abolitionist 39 explorer 38 Ojibwe 38 Gettysburg Address 38 Custer 38 Confederacy 38 log cabin 38 sesquicentennial 38 abolitionists 38 steamship 38 horseback 38 Genghis Khan 37 #th century 37 Rudyard Kipling 37 Civil War era 37 naturalists 37 Charles Lindbergh 37 Winston Churchill 37 adventurer 37 Klondike 37 adventurers 37 Mississippi River 37 ancestors 37 Fort Sumter 37 Queen Victoria 37 expeditions 36 WWI 36 Founding Fathers 36 Emily Dickinson 36 Santa Fe Trail 36 Tlingit 36 slaves 36 D. Rockefeller 36 Baffin Island 36 naturalist 36 Earhart 36 Alan Shepard 36 Breckinridge 36 Colonial Williamsburg 36 Appalachian Mountains 36 Jack Kerouac 36 Dirk Kempthorne 36 Underground Railroad 36 William Shakespeare 35 Sesquicentennial 35 Fort McHenry 35 Northwest Passage 35 John Philip Sousa 35 Bering Strait 35 riverboats 35 nineteenth century 35 bison 35 Wampanoag 35 Continental Divide