Timelines are a valuable tool for understanding a process that unfolds over time. Timeline.JS is an open-source, online, free site that can help you build an impressive timeline in a few minutes. You will need to use a Google Spreadsheet to work with Timeline.JS.
This provides step-by-step instructions as does the TimelineJS website.
This tutorial provides step-by-step instructions for embedding a timeline created in TimelineJS into your WordPress site.
This tutorial provides instructions on embedding a timeline in OMEKA.