By definition primary sources are originals, and although there may be copies, many may only be housed in museums or archives.
One way around this dilemma is to look for primary sources within secondary sources, such as the The Declaration of Independence in a book about the Founding Fathers or a Roman proclamation in a book about the Roman Empire.
Be creative in thinking about what a primary source might be for your particular project and where you might find access to it without having to travel to see the original. Some of the specific databases below contain accessible primary sources, for example. Others might be discovered on the web in digitized form.
Remember to ask your professor whether a primary source from within a secondary source would be appropriate for your assignment.
One of the newest, most exciting, and open source discovery platforms is the Digital Public Library of America. It includes almost eight million items form America's libraries, archives, and museums. These include digitized books, photographs, and historical documents from the Smithsonian, the National Archives, major research universities, and digital consortia.
In addition, the Library of Congress, with the support of the United Nations Educational, Cultural and Scientific Organization (UNESCO), and in cooperation with libraries, archives, museums, educational institutions, and international organizations from around the world, is hosting the World Digital Library. To-date, the World Digital Library contains over 10,000 items about nearly 200 countries.