Question: Who was the U.S. senator that sponsored the construction of Mount Rushmore?
About the article "Mount Rushmore", section "Abstract".

Candidate passages:
The construction of Mount Rushmore National Memorial took about 14 years, from 1927 to 1941. 
The Mount Rushmore National Memorial is a sculpture carved into the granite face of Mount Rushmore (Lakota Sioux name: Six Grandfathers) near Keystone, South Dakota, in the United States.
Sculpted by Danish-American Gutzon Borglum and his son, Lincoln Borglum, Mount Rushmore features sculptures of the heads of four United States presidents: George Washington (1732–1799), Thomas Jefferson (1743–1826), Theodore Roosevelt (1858–1919), and Abraham Lincoln (1809–1865).
The entire memorial covers and is above sea level.
South Dakota historian Doane Robinson is credited with conceiving the idea of carving the likenesses of famous people into the Black Hills region of South Dakota in order to promote tourism in the region.
Robinson's initial idea was to sculpt the Needles; however, Gutzon Borglum rejected the Needles site because of the poor quality of the granite and strong opposition from Native American groups.
They settled on the Mount Rushmore location, which also has the advantage of facing southeast for maximum sun exposure.
Robinson wanted it to feature western heroes like Lewis and Clark, Red Cloud, and Buffalo Bill Cody, but Borglum decided the sculpture should have a more national focus and chose the four presidents whose likenesses would be carved into the mountain.
After securing federal funding through the enthusiastic sponsorship of "Mount Rushmore's great political patron," U.S.
Senator Peter Norbeck, construction on the memorial began in 1927, and the presidents' faces were completed between 1934 and 1939.
Upon Gutzon Borglum's death in March 1941, his son Lincoln Borglum took over construction.
Although the initial concept called for each president to be depicted from head to waist, lack of funding forced construction to end in late October 1941.
Mount Rushmore has become an iconic symbol of presidential greatness and has appeared in works of fiction, and has been discussed or depicted in other popular works.
It attracts nearly three million people annually.
Iron Mountain is a peak in the Black Hills of South Dakota, notable for the fact that U.S. Route 16A was purposely built directly over its summit to provide scenic views of Mount Rushmore National Memorial. 
USS "Rushmore" (LSD-47) is a "Whidbey Island"-class dock landing ship of the United States Navy.
She was the second Navy ship to be named for the Mount Rushmore National Memorial in the Black Hills of South Dakota.
She is the seventh ship in her class of dock landing ships and the fourth ship in that class to serve in the United States Pacific Fleet.
"Rushmore" (LSD-47) was laid down on 9 November 1987, by the Avondale Shipyards, New Orleans; launched on 6 May 1989, sponsored by Mrs. Meredith Brokaw, wife of NBC News anchorman Tom Brokaw; and commissioned on 1 June 1991, at New Orleans. 
After reading about Stone Mountain, Robinson was suddenly inspired to sculpt the Needles, several pillars made of granite, into likenesses of famous people.
He hoped that such a sculpture would attract greater tourism to South Dakota.
After failing to contact Lorado Taft, who was ill, Robinson gained the support of Gutzon Borglum.
He was also backed by Senator Peter Norbeck.
Robinson began efforts to raise funds for the project and to receive permission to carve the Needles.
The funds were denied, and many groups including Native Americans disliked the idea.
Environmentalist Cora Johnson of the "Hot Springs Star" felt that such a carving would destroy the landscape.
On Borglum’s second meeting with Robinson, Borglum switched the location of the carving from the Needles to Mount Rushmore.
Borglum also decided that the sculptures should have a larger national focus, and he selected the four presidents.
The headquarters of the project, south of Mount Rushmore, became known as Doane Mountain.
In 1929, president Calvin Coolidge finally signed a bill which created to a commission to oversee the sculpting.
Robinson failed to become part of the commission, which greatly disappointed him.
Following his retirement from being a historian, he returned to farming, and lived to see the completion of Mount Rushmore.
He died on November 27, 1946 in Pierre, South Dakota.