Complex sentence: Development was hampered by adverse legislation from the 1830s and the rapid development of internal combustion engine technology in the 1900s, led to the demise of the steam engine as a source of propulsion of vehicles on a commercial basis.
Split into simpler sentences: Development was hampered by adverse legislation from the 1830s and the rapid development of internal combustion engine technology in the 1900s. This led to their demise: of the steam engine as a source of propulsion of vehicles on a commercial basis.