How old is the Washington Monument?

The Washington Monument is one of the most recognizable sights in Washington DC, situated on the National Mall and near the Lincoln Memorial. It is one of several monuments that were constructed in celebration of George Washington, but because of its sheer size, it was both expensive and time-consuming to construct. While the first stone was laid in 1848, the monument was not officially opened for another forty years: it was October 1888 before this could happen.
One key reason it took so long to build this monument was the intervention of the American Civil War. Not only was there a lack of labor, the US government was financially depleted by the devastation of the Civil War, which rendered it unable to justify spending money on the construction of this monument until 1877, when construction resumed after its halt in 1854.