StoryMapJS is a free tool to help you tell stories on the web that highlight the locations of a series of events. [description taken from Knight Lab website]
1. On https://storymap.knightlab.com/, login using your Google account.
2. For each slide of your StoryMap, upload or link to an image, add a caption, and enter a location.
3. When you are done creating slides, click Share. The site will provide you with a share link, and an iframe embed code. Copy the code and paste it on your web page.
Additional directions, FAQs, and help are available on the Knight Lab website.