William N. Monroe first brought his family to California in 1875, after a successful ten year period of building railroads in the Midwest. Monroe, a former school teacher and army officer during the Civil War, had met Charles Crocker of "Big Four" fame, and Crocker had persuaded Monroe to relocate. The family set up headquarters in Los Angeles while Monroe was building railroads throughout the state for the Southern Pacific Railroad.
From 1879 to 1882, Monroe served on the Los Angeles City Council, meeting other leaders who would play an important role in Monrovia's history several years later.
In 1882, the Monroes moved to Texas while W.N. was involved in another construction project. At the conclusion of this work in 1884, the Monroes returned to California with a railroad car of mules, a tidy nest egg, and a deep desire for a permanent home. The mules were sold for a nice profit in Los Angeles, with the exception of sixteen which were retained by Monroe and would also play their role in Monrovia's history. Part of the proceeds were invested in a spring wagon and span of ponies with which the Monroes began their search in Southern California for the perfect home site. This was in April of 1884.
In the course of their travels they came to the San Gabriel Valley, where E.J. "Lucky" Baldwin had subdivided the eastern portion of his vast Rancho Santa Anita into thirty acre parcels. With Baldwin as their guide, the Monroes explored the area which would one day become Monrovia. They were deeply impressed by the locale and the native oak trees. Baldwin undoubtedly pointed out the water and natural protection from frost offered by the Santa Anita and Sawpit Canyons to the north. The Monroes were satisfied; this was the place.
As soon as the purchase was arranged, the Monroes moved onto their land, setting up housekeeping in a tent under a spreading oak tree at what is now the southeast corner of Hillcrest and Magnolia. Construction was begun on a temporary home, and Monroe began clearing the land with his mules and a crew of 80 men. His orders were to clear the land, but to leave the oak trees. By the summer of 1884, the Monroes had moved into their temporary cottage and plans were under way for a permanent home. For its location, the Monroes selected an oak-studded site which had attracted them on their first visit. This home was completed in May of 1885.
The Monroes were gracious hosts who frequently entertained the friends made in Los Angeles during their residence there. By the end of 1885, three of these friends, Judge J.D. Bicknell, J.F. Crank, and E.F. Spence, had also purchased acreage from Baldwin. In the spring of 1886 these men, together with Monroe and J. F. Falvey, the foreman of Baldwin's ranch, decided to establish a town on their combined holdings. In honor of W.N. Monroe, the new town was to be named Monrovia. Two engineers laid out a sixty acre town site with streets named for trees, flowers, and ladies, and lots were first offered for sale on May 17, 1886. Monrovia, Gem City of the Foothills, was born.