Harper sprang up as the result of a few different factors. In 1891, a new railroad was completed.  It ran between Newport Beach and Santa Ana and had several large farms along the route.  A railroad station was built so that the farmers could load their cars.  The station was Thurin Station, which was just east of the intersection of Fairview and Newport Boulevard.

However, Harper, a large farm just south of Thurin Station chose to build its own separate siding and loading platform.

More people began to move to Harper when a water distribution system was installed between 15th Street, 23rd Street, Newport Boulevard and Irvine Avenue in 1906.  The first year, more than 200 parcels of land were sold.  By 1908, there were so many people that Harper opened both its own school and its first store.

As the water distribution system was extended, so were the number of houses and people in the city.

Water was a major factor in the growth of Harper. The farmers of Harper grew many foods including oranges, lima beans, lemons, apricots, avocados and apples and needed a good source of water so that their crops could thrive.

By 1920, Harper had grown to around 300 people and continued to thrive unlike Fairview and Paularino.