Question: What is the birthday of the man who succeeded Mo Cowan in 2013 for United States Senator from Massachusetts?

Context paragraphs:
Mo Cowan: William Maurice "Mo" Cowan (born April 4, 1969) is an American politician and lawyer who served as a United States Senator from Massachusetts in 2013.  He previously served as legal counsel and chief of staff to Massachusetts Governor Deval Patrick.  Patrick appointed him on January 30, 2013, on an interim basis to fill the vacancy left by fellow Democrat John Kerry, who resigned to become Secretary of State.  He declined to run in the 2013 special election to complete the remainder of Kerry's term.  He was succeeded by fellow Democrat Ed Markey.  He is now the Chief Operating Officer of ML Strategies, an affiliate of Mintz Levin.

Ed Markey: Edward John Markey (born July 11, 1946) is an American politician and member of the Democratic Party who is the junior United States Senator from Massachusetts, in office since 2013.  From 1976 to 2013 he served as the U.S. Representative for Massachusetts 's 5 congressional district .  He previously served in the Massachusetts House of Representatives from 1973 to 1976.

Tom Udall: Thomas Stewart Udall (born May 18, 1948) is the senior United States Senator from New Mexico and a member of the Democratic Party.  First elected to the Senate in 2008, he represented  's 3 congressional district as a member of the United States House of Representatives from 1999 to 2009, and was the Attorney General of New Mexico from 1991 to 1999.  A member of the Udall family, he is the son of Stewart Udall, the nephew of Mo Udall, and the cousin of Mark Udall.  He is the current dean of New Mexico's Congressional Delegation.

Liberty Hall (New Jersey): The Liberty Hall Museum in Union, Union County, New Jersey, United States, is an American historic site.  Built in 1772 as a fourteen-room Georgian-style house, Liberty Hall stands today a fifty-room Victorian Italianate mansion.  Liberty Hall has been home to many historical figures and was the home of William Livingston, the first Governor of New Jersey, who served from 1776 to 1790; United States Supreme Court Justice Henry Brockholst Livingston; the Kean political dynasty, including Susan Livingston Kean, widow of Continental Congress delegate John Kean, United States Senator and Congressman John Kean, and Captain John Kean, son of United States Senator Hamilton Fish Kean; and, in its first year of occupancy, future Treasury Secretary Alexander Hamilton.  Liberty Hall has had visitors of such stature as George Washington, Martha Washington, Lewis Morris, Marquis de Lafayette, Elias Boudinot, and John Jay, the latter of whom was married there.

Harry F. Byrd: Harry Flood Byrd Sr. (June 10, 1887 – October 20, 1966) of Berryville in Clarke County, Virginia, was an American newspaper publisher, and for four decades political leader of the Democratic Party in Virginia as head of a political faction that became known as the Byrd Organization.  Byrd served as Virginia's governor from 1925 until 1929, then represented the Commonwealth as a United States Senator from 1933 until 1965.  He came to lead the "conservative coalition" in the United States Senate, and opposed President Franklin Delano Roosevelt, largely blocking most liberal legislation after 1937.  His son Harry F. Byrd Jr. succeeded him as U.S. Senator, but ran as an Independent following the decline of the Byrd Organization.

Deb Fischer: Debra Strobel Fischer (born March 1, 1951) is the senior United States Senator from the state of Nebraska.  Previously, she was a two-term member of the Nebraska Legislature, representing the 43rd District.  She defeated former United States Senator Bob Kerrey in the election held on November 6, 2012, and assumed one of Nebraska's two Senate seats in January 2013.

William J. Pascrell III: William J. Pascrell III is an American lobbyist with the Princeton Public Affairs Group, and has been the Passaic County Counsel.  He has worked for United States Senator and Governor Jon Corzine, United States Senator Frank Lautenberg, United State Senator Robert Menendez, Congressman Robert Roe, Herb Klein and Albio Sires as well as Governor James E. McGreevey.  Pascrell earned an Emmy Award nomination in the category of Outstanding Talk Program Series for "The Battling Bills," a program he created jointly with Bill Palatucci.  Pascrell graduated from Rutgers University and the Eagleton Institute of Politics, and earned a Juris Doctor from Seton Hall University.  He is the son of Congressmen Bill Pascrell.

Samuel C. Pomeroy: Samuel Clarke Pomeroy (January 3, 1816 – August 27, 1891) was an United States Senator from Kansas in the mid-19th century, serving in the United States Senate during the American Civil War.  Pomeroy served in the Massachusetts House of Representatives.  A Republican, he also was the mayor of Atchison, Kansas, from 1858 to 1859, the second president of the Atchison, Topeka and Santa Fe Railroad and the first president to oversee any of the railroad's construction and operations.  Pomeroy succeeded Cyrus K. Holliday as president of the railroad on January 13, 1864.

Ted Kennedy: Edward Moore "Ted" Kennedy (February 22, 1932 – August 25, 2009) was an American politician and lawyer who served as a United States Senator from Massachusetts for over forty years from 1962 until his death in 2009.  A member of the Democratic Party, he was the second most senior member of the Senate when he died and was the fourth-longest-continuously-serving senator in United States history, having served there for almost 47 years.  Ted Kennedy was the most prominent living member of the Kennedy family for many years, and he was also the last surviving, longest-living, and youngest son of Joseph P. Kennedy, Sr. and Rose Kennedy.  He was the youngest brother of John F. Kennedy, the 35th President of the United States and Senator Robert F. Kennedy, both victims of assassination, and the father of Congressman Patrick J. Kennedy.

John F. Kennedy presidential campaign, 1960: The 1960 presidential campaign of John F. Kennedy, a United States Senator from Massachusetts, began on January 2, 1960, when Kennedy formally announced his candidacy for 35th President of the United States, replacing incumbent President of the United States Dwight D. Eisenhower.  Kennedy was nominated by the Democratic Party at the Democratic National Convention of 1960, taking place between July 11 and July 15, 1960.  On July 15, 1960, Kennedy named Senator Lyndon B. Johnson of Texas as his official running mate.  Kennedy and Johnson won the election on November 8, 1960, defeating incumbent Vice President and Republican nominee Richard Nixon, who would later go on to be the 37th President of the United States.  Kennedy and Johnson were sworn in as 35th President and 37th Vice President of the United States on January 20, 1961 respectively.  Kennedy would serve as President of the United States until his death in November 1963.

Supporting paragraphs: Mo Cowan Ed Markey
Answer: July 11, 1946