The cornerstone was laid in 1848 but construction had to be stopped in 1854 due to a lack of funding. Funding in 1876 allowed resumption on the building of the monument which was completed in 1888.
If you look closely at the monument you will notice a difference in color of the marble about a third of the way up. This is because when they resumed construction they used a slightly different color of marble.
The final cost of the monument was $1,187,710. The architect was Robert Mills.
This amendment ended slavery.
JFK forced US Steel and other steel companies to rescind a $6 per ton hike on steel prices which JFK considered to be both a violation of their promise to him not to raise their prices as well as an inflationary decision.
In a later comment he said: "I have never considered the members of the NAM to be among my most fervent supporters, except for a few who thought I was my father's son."
That got a laugh. His dad, of course, was a very successful businessman himself.