That list of biblical references running down the gutter of each page the ESV Study Bible is a compilation of thousands of cross-references that point to other thematically related parts of Scripture. All told the ESVSB has 80,000 of those cross-references.
There’s a history to who actually made those connections. The references found in the ESVSB were compiled by a team of Bible scholars from Oxford and Cambridge Universities over 100 years ago. Their work was first used in the English Revised Version (RV), a version that appeared in 1881.
A few years back Lutheran pastor Christoph Römhild wondered if an infographic could capture cross-references like these for the purpose of visualizing the tapestry of Scripture. He contacted Chris Harrison, who said yes, and together they created this:
Each bar along the bottom represents a chapter from Genesis (left) to Revelation (right). The length of the bar correspond to the length of the chapter (Psalm 119 is easy to find in the middle). The cross-references are arched and colored by arch length. In all this graphic represents 63,779 colorful cross-references (I’m unsure how they arrived at this number, cross-referencing being something of an art — the Thompson’s Chain-Reference Bible has over 100,000, for example).
Beautiful graphic, isn’t it? This is a wonderful visual reminder of the thematic unity of Scripture, and it serves as a great personal reminder to read every verse in light of the bigger biblical storyline.
You can find a large version of the graphic and more information here.