Day 14 - Sun 22nd March: Iwo Jima Memorial, Washington D.C.

Here's some info, lifted straight from Wiki:

The memorial is dedicated to all personnel of the United States Marine Corps (USMC) who have died in the defense of their country since 1775. The design of the massive sculpture by Felix de Weldon was based on the iconic photo of the raising of the Flag on Iwo Jima by Associated Press photographer Joe Rosenthal.

Day 13 - Sat 21st March: Lincoln Memorial, Washington D.C.

This year sees the 200th Anniversary of Abraham Lincoln's birth, so there's quite a few exhibits dedicated to him in a number of WDC's museums.
He grew his beard in late 1860. He was in office from March 1861.
I presume these two events are not related.

Day 4 - Thurs 12th March: The Statue of Liberty, NYC

Does what it says on the tin.
For any photo geeks out there, this one was taken with a polarising filter.