It was built in 1910 to serve the Elgin National Watch Company two blocks to the west.

The two-story observatory provided data on time that was scientifically accurate to a tenth of a second.

The observatory was an important part of the company's legacy, and they even changed their motto to reflect this.

In 1850, the Galena and Chicago Union Railroad connected to the city, bolstering the economy.

Former Chicago mayor Benjamin Wright Raymond suggested Elgin as a location for the factory.

In 1908, Theodore Roosevelt finally demanded that the United States Bureau of Standards encourage precise timing across the nation.

An astronomer would press a button every time a star appeared to cross one of the wires, which would send an impulse to the clock.

In the factory, the sounder audibly ticked off the seconds so that workers could set the watches accurately.

The Illinois government also equipped the observatory with thermometers, a thermograph, barometer, barograph, rain gauge, and weather vane.

[2] The Great Depression hit the Elgin National Watch Company badly.

Following World War II, Swiss manufacturers began to dominate the pocket watch industry.

The final blow came in 1950, when the United States Time Corporation introduced a cheap wristwatch that could be discarded and repurchased for less than the cost of repair.

Concrete piers were dug 60 feet (18 m) down into this layer to secure the telescope and Riefler clocks.

[2] A steel doors leads to the entrance of the observatory segment, where there is a stairway to the second floor and a small lavatory.

A set of airlock style doors leads to a temperature controlled room with two of the four Riefler clocks on one of the piers.

The observatory segment is a two-story, concrete, domed octagon, covered with sheet metal.

A staircase in the northeast of this room leads to the tin roof, now covered with aluminum paint.