Hacienda La Igualdad was established by Quintín Ramirez de Arellano Falto de Armedo (1815-1888) and his wife Carmen Lugo Rossy ca 1840.  Humberto García Muñiz in his book Sugar and Power in the Caribbean, states that in 1891 the then one thousand one hundred cuerdas Hacienda La Igualdad was owned by Ubaldino Ramirez de Arellano Lugo (1840-1894), the son of Quintin and Carmen.

Ubaldino married three times, first time to Paula Alfonso without any descendants being born from that union.  He married a second time Lorenza Rosell Carbonell from which union Alfredo Ramirez de Arellano Rosell (1882-1946) was born.  He married a third time Maria Ana “Mary” Quiñones Quiñones from which marriage were born Gustavo Adolfo Ramirez de Arellano Quiñones (1888- ) who in 1920 was an Engineer with the Health Department in San Juan and Haydée (1891-1983) Ramirez de Arellano Quiñones.

The hacienda was inherited by Alfredo Ramirez de Arellano Rosell who in the early 1900's leased the factory and eight hundred forty four acres of land for a ten year period to the South Porto Rico Sugar Co.  As a result, Hacienda La Igualdad stopped milling operations and sugarcane grown in its lands was then processed at the nearby Guanica Central.  Ramirez de Arellano Rosell was also part owner of Hacienda Isabel Josefa and member of the group that acquired Central Igualdad in 1925.  

The 1977 Historic American Engineering Record (HAER Report) includes drawings and photos and states the specifications of the machinery then found at this hacienda.  It states that the beginning of Hacienda La Igualdad dates back to 1840 and that the cane crushing machinery photographed below dates from between 1860 and 1870.  The machinery pictured below is a single column, slide-valve, side-crank beam engine of unknown manufacturer that drove the three-role cane crushing mill.  Most of the machinery was intact during in 2015 as was the octagonal chimney.  All the equipment that was then in open air used to be inside the factory building of which only ruins of the foundation walls and arches remain.

The steam engine is of unusual architectural design having an open, decorative, single pedestal cast-iron column supporting a cast-iron beam. The engine has a 12-inch bore and 40-inch stroke with a 15-foot diameter cast-iron flywheel that turned at approximately 20 rpm, with individual spoke and rim castings bolted together.  Connected to the crankshaft and flywheel is a single, 15-foot diameter reduction gear coupled to a three-role cane crushing mill.

Hacienda La Igualdad location is on PR-332 between the town of Guanica and Barrio Ciénaga on the north bank of the Rio Loco.  As can be seen from the picture below, the chimney suffered substantial damage during the series of earth tremors that happened in the southwestern part of Puerto Rico in 2020.