Complex sentence: While inchoate plans for the ring had been in place for many decades, parts of it, including several bridges, were built during the recession of the 1930s, when dikes were constructed to provide employment opportunities.
Split into simpler sentences: While inchoate plans for the ring had been in place for many decades. Parts of it, including several bridges, were built during the recession of the 1930s, when dikes were constructed to provide employment opportunities.