Georeferencing with the David Rumsey Georeferencer was more challenging than expected. I had a hard time pinpointing the common points between the maps to locate a full version of Somalia, as the coordinates of the Horn would show up partially in other maps, such as those of the Arab Peninsula and North Africa, instead of showing the full extent of the Horn of Africa.
Although the David Rumsey Historical Map Collection holds over 150,000 digital maps and images from the 16th and 21st centuries, many of which are world and regions maps, therefore, not helpful for georeferencing projects that need locations or points beyond major cities and country demarcations. Assigning geographical locations at more exact points like cities and counties requires a more detailed map. Hence, I have a deeper respect for the work and effort that goes into spatial projects, especially as you go beyond georeferencing and overlaying maps to building on top of those map layers, 3D models, and the like. Furthermore, an individual can create a story with a georectified map by layering multiple georeferenced maps and looking at changes over time, and this would be great for maps pertaining to topography and land-use changes.
Click here to access my georeferenced image of Somalia and the Horn of Africa. It is also available in downloadable files like TileJSON, or you can import them straight into your ArcGIS or QGIS.