Complex sentence: The Egg Company strove to assert its claim to South East Farallon (SEFI) and the adjoining West End (or Maintop Island); it surveyed the islands, obtained a school warrant, and constructed buildings, paths and landing facilities.
Split into simpler sentences: The Egg Company strove to assert its claim to South East Farallon (SEFI) and the adjoining West End (or Maintop Island). It surveyed the islands, obtained a school warrant, and constructed buildings, paths, and landing facilities.