Online:
* Wikimedia Commons: This repository has a vast collection of free-to-use images, including several portraits of John Adams.
* The John Adams Library: The official website of the John Adams Presidential Library has a gallery of images, including portraits and photographs.
* National Portrait Gallery: The Smithsonian's National Portrait Gallery website has a searchable database of portraits, including several of John Adams.
* Google Images: A simple search on Google Images will bring up a wide range of images, from paintings to photographs.
* Art museums online collections: Many art museums have online collections that you can browse, including the Metropolitan Museum of Art, the National Gallery of Art, and the Museum of Fine Arts, Boston.
Offline:
* Libraries: Many libraries have books about John Adams, which often include portraits.
* Museums: Museums dedicated to American history, such as the Smithsonian's National Museum of American History, often have portraits of John Adams on display.
* Art galleries: Private art galleries may also have portraits of John Adams for sale or on display.
When searching for images, it's helpful to use keywords such as "John Adams portrait," "John Adams painting," or "John Adams photograph." You can also specify the type of image you're looking for, such as "oil painting," "engraving," or "photo."
It's important to note that some images may be copyrighted. Be sure to check the licensing information before using any image for commercial purposes.