Susan Margaret Collins (born December 7, 1952) is the junior United States Senator from Maine and a member of the Republican Party. First elected to the Senate in 1996, she is the ranking member of the Senate Committee on Homeland Security and Governmental Affairs.

One of six children, Susan Collins was born in Caribou, Maine, where her family has operated a lumber business since 1844. Her parents, Patricia R. (née McGuigan) and Donald F. Collins, each served as mayor of Caribou; her father also served in both houses of the Maine Legislature. Her mother was born in Barranca-Bermeja, Colombia, to American parents. Her uncle, Samuel W. Collins, Jr., sat on the Maine Supreme Judicial Court from 1988 to 1994. Collins attended Caribou High School, where she was president of the student council. During her senior year of high school in 1971, Collins was chosen to participate in the U.S. Senate Youth Program, through which she visited Washington, D.C. for the first time and engaged in a two-hour conversation with U.S. Senator Margaret Chase Smith (R-ME). Collins is the first program delegate elected to the Senate and currently holds the seat once held by Smith.

Olympia Jean Snowe (née Bouchles; born February 21, 1947) is the senior United States Senator from Maine and a member of the Republican Party. Snowe has become widely known for her ability to influence the outcome of close votes, including whether to end filibusters. She and her fellow Senator from Maine, Susan Collins, are regarded as leading moderates within their party. In 2006, she was named one of America's Best Senators by Time Magazine. On February 28, 2012, Snowe announced that she will not seek reelection in November 2012, and will retire when her third term ends on January 3, 2013.

Snowe was born Olympia Jean Bouchles in Augusta, Maine, the daughter of Georgia (née Goranites) and George John Bouchles. Her father immigrated to the United States from Sparta in Greece, and her maternal grandparents were also Greek. She is a member of the Greek Orthodox Church.

Snowe's early life had its share of tragedies; when she was nine, her mother died of breast cancer, and her father died of heart disease barely a year later. Orphaned, she was moved to Auburn, Maine, to be raised by her aunt and uncle, a textile mill worker and a barber, respectively, along with their five other children. Her brother John was raised separately, by other family members. Within a few years, disease would also claim her uncle's life.

Margaret Madeline Chase Smith (December 14, 1897 – May 29, 1995) was an American politician. A member of the Republican Party, she served as a U.S Representative (1940-1949) and a U.S. Senator (1949-1973) from Maine. She was the first woman to serve in both houses of the United States Congress, and the first woman to represent Maine in either. A moderate Republican, she is perhaps best remembered for her 1950 speech, "Declaration of Conscience," in which she criticized the tactics of McCarthyism.

Smith was an unsuccessful candidate for the Republican nomination in the 1964 presidential election, but was the first woman to be placed in nomination for the presidency at a major party's convention. Upon leaving office, she was the longest-serving female Senator in history, a distinction that was not surpassed until January 5, 2011, when Senator Barbara Mikulski was sworn in for a fifth term.

Margaret Chase was born in Skowhegan, Maine, to George Emery and Carrie Matilda (née Murray) Chase. She was the oldest of six children, only four of whom survived to adulthood. Her father was of English ancestry, a descendant of immigrants to the United States in the 17th century; her great-great grandfather commanded an artillery company during the War of 1812, and her grandfather served in the Union Army during the Civil War. Her mother's family was French Canadian, having immigrated from Quebec in the middle of the 19th century; her grandfather, Lambert Morin, changed his name to John Murray to avoid anti-French Canadian and anti-Catholic prejudice. Her father was the town barber, and her mother worked as a waitress, store clerk, and shoe factory worker.

Carolyn Jane Bosher Maloney (born February 19, 1946) is the U.S. Representative for New York's 14th congressional district, serving since 1993. She is a member of the Democratic Party. The district, popularly known as the "silk stocking district", includes most of Manhattan's East Side; Astoria and Long Island City in Queens; and Roosevelt Island.

Carolyn Maloney was born in Greensboro, North Carolina, the daughter of Christine Elizabeth (née Clegg) and Ralph George Bosher. She graduated from Greensboro College. In 1970, she visited New York City and decided to stay. For several years, she worked as a teacher and an administrator for the New York City Board of Education. In 1977, she obtained a job working for the New York State Legislature and held senior staff positions in both the State Assembly and the State Senate.Maloney is the first woman to represent New York’s 14th Congressional District; the first woman to represent New York City’s 7th Council district (where she was the first woman to give birth while in office); and was the first woman to Chair the Joint Economic Committee, a House and Senate panel that examines and addresses the nation’s most pressing economic issues. Maloney is widely viewed as "a strong champion for women's rights, supporting reproductive rights, promoting economic justice for women and pursuing equality for all through such actions as reintroducing the Equal Rights Ammendment. Nicholas Kristoff said of her work in the battle against human trafficking: "No one has been a greater champion than Carolyn Maloney" in the fight against human trafficking. Her question: "Where are the women?" asked at a hearing by the Government Oversight Committee sparked a firestorm of controversy in the 2012 election cycle.

Angus S. King, Jr. (born March 31, 1944) served two terms as the 72nd Governor of Maine from 1995 to 2003. Since 2004, King has been a lecturer at Bowdoin College teaching a course called "Leaders and Leadership"; in the fall of 2009, he taught a similar course at Bates College. He also became employed at a law firm and a mergers and acquisitions advisory firm (Leaders LLC) in Portland, Maine. He currently works on issues of sustainable and renewable energy. In spring 2009 he endorsed the Maine Green Energy Project, a summer program for young people to learn to build and advocate for green energy in Maine. He is an independent candidate in the 2012 election for one of Maine's two seats in the U.S. Senate.

King was born in Virginia, but spent most of his adult years in the state of Maine. He graduated from Dartmouth College in 1966 and the University of Virginia School of Law in 1969. King entered private law practice in Brunswick, Maine.

In the 1980s King served as Vice President of a company which developed alternative energy (hydro and biomass) projects in New England. In 1989 King founded Northeast Energy Management, Inc. The company developed, installed, and operated large-scale electrical energy conservation projects at commercial and industrial facilities throughout south-central Maine.