What dose the term sectionalism mean

Sectionalism generally means being loyal to only a part, instead of the whole.

Explanation:

Examples can be seen more in a country term, taking the US for example. People in California may be more loyal to California and may put state priorities in front of national securities. Another example can be the South, which mostly contain rural townspeople and farmers, and they may be loyal to only politicians who can support their way of life. This is a "section" of people who are only loyal to a person because of such & such benefit.

in the 1800s, locomotives powered by steam made transportation faster and cheaper. the resulting rapid growth of railroads led to the connection of the atlantic and pacific railroad in oklahoma city in 1897.

in the last years of the century, the improvement of steam-based engines the expansion and growth of railroads. this growth increased when the companies started to build and expand, such as the atlantic and pacific railroad, which connected new mexico with california, and missouri with oklahoma. many of these new networks were built in oklahoma, and these changes transportation henceforward.