Complex sentence: Steamboats were beginning to see strong competition from the railroads after the rail lines had been replaced following the Civil War, which may have been a factor in Hinde's decision to switch from the river navigation business to the railroad business in the following years.
Split into simpler sentences: Steamboats were beginning to see strong competition from the railroads after the rail lines had been replaced following the Civil War. This may have impacted Hinde's decision to switch from the river navigation business to the railroad business in the following years.