Complex sentence: Major accomplishments included the assembly of the collection of early American tools now housed in the Mercer Museum, and for his tile work which makes up the floor of the Pennsylvania State Capitol Building in Harrisburg, Pennsylvania and many other noteworthy buildings and houses.
Split into simpler sentences: Major accomplishments included the assembly of the collection of early American tools now housed in the Mercer Museum. Mercer's tile work which makes up the floor of the Pennsylvania State Capitol Building in Harrisburg, Pennsylvania and many other noteworthy buildings and houses.