question: Which country Tad Lincoln's mother is from?
context: [["Nayelly Hern\u00e1ndez", ["Nayelly Hern\u00e1ndez( born 23 February 1986) is a former Mexican female professional squash player.", "She has represented Mexico internationally in several international competitions including the Central American and Caribbean Games, Pan American Games, Women's World Team Squash Championships.", "Nayelly achieved her highest career ranking of 57 in October 2011 during the 2011 PSA World Tour.", "Her husband Chris Walker whose nationality is English is also a professional squash player.", "She joined the Trinity College in 2008 as the first Mexican female to join a US college for squash and graduated in 2010."]], ["Baglan Mailybayev", ["Baglan Mailybayev( in Kazakh \u0411\u0430\u0493\u043b\u0430\u043d \u0410\u0441\u0430\u0443\u0431\u0430\u0439\u04b1\u043b\u044b \u041c\u0430\u0439\u043b\u044b\u0431\u0430\u0435\u0432) was born on 20 May 1975 in Zhambyl region, Kazakhstan.", "His nationality is Kazakh.", "He is a politician of the Republic of Kazakhstan, Deputy Head of the Presidential Administration of the Republic of Kazakhstan, Doctor of Law( 2002)( under the supervision of Professor Zimanov S.Z.- scientific advisor and academician of National Academy of Sciences of the Republic of Kazakhstan) and Ph.D. in Political Science( 1998)."]], ["Rumbold of Mechelen", ["Saint Rumbold( or\" RumoldRomuold\") was an Irish or Scottish Christian missionary, although his true nationality is not known for certain.", "He was martyred near Mechelen by two men, whom he had denounced for their evil ways.", "Saint Rumbold's feast day is celebrated by the Roman Catholic Church, and Western Rite Orthodox Churches, on 24 June; and it is celebrated in Ireland on 3 July.", "He is the patron saint of Mechelen, where St. Rumbold's Cathedral possesses an elaborate golden shrine on its high altar, containing relics attributed to the saint.", "It is rumoured that his remains are buried inside the cathedral.", "Twenty- five paintings in the choir illustrate his life."]], ["Eleni Gabre-Madhin", ["Eleni Zaude Gabre- Madhin, an Ethiopian economist with Swiss nationality, is a former Chief Executive Officer of the Ethiopia Commodity Exchange( ECX).", "She has had many years of experience working on agricultural markets \u2013 particularly in Sub- Saharan Africa \u2013 and has held senior positions in the World Bank, the International Food Policy Research Institute( Washington), and United Nations( Geneva)."]], ["Tad Lincoln", ["Thomas \"Tad\" Lincoln III (April 4, 1853 \u2013 July 15, 1871) was the fourth and youngest son of Abraham and Mary Todd Lincoln.", "The nickname \"Tad\" was given to him by his father, who observed that he had a large head and was \"as wiggly as a tadpole\" when he was a baby.", "Lincoln was known to be impulsive and unrestrained, and he did not attend school during his father's lifetime.", "He had free run of the White House, and there are stories of him interrupting presidential meetings, collecting animals, and charging visitors to see his father.", "He died at the age of 18 on July 15, 1871, in Chicago."]], ["Roberto Savio", ["Roberto Savio( born in Rome, Italy, but also holding Argentine nationality) is a journalist, communication expert, political commentator, activist for social and climate justice and advocate of global governance.", "He has spent most of his career with Inter Press Service( IPS), the news agency which he founded in 1964 along with Argentine journalist Pablo Piacentini.", "Savio studied Economics at the University of Parma, followed by post -graduate courses in Development Economics under Gunnar Myrdal, History of Art and International Law in Rome.", "He started his professional career as a research assistant in International Law at the University of Parma."]], ["Mary Todd Lincoln", ["Mary Todd Lincoln (Mary Ann Todd; December 13, 1818 \u2013 July 16, 1882) was the wife of the 16th President of the United States, Abraham Lincoln, and as such the First Lady of the United States from 1861 to 1865.", "She dropped the name Ann after her younger sister, Ann Todd (Clark), was born, and did not use the name Todd after marrying.", "Mary was a member of a large, wealthy Kentucky family, and was well educated.", "After finishing school during her teens, she moved to Springfield, Illinois, where she lived with her married sister Elizabeth Edwards.", "Before she married Abraham Lincoln, Mary was courted by his long-time political opponent Stephen A. Douglas.", "She and Lincoln had four sons together, only one of whom outlived her.", "Their home of about 17 years still stands at Eighth and Jackson Streets in Springfield, Illinois.", "She supported her husband throughout his presidency.", "She witnessed his fatal shooting when they were together in the President's Box at Ford's Theatre on Tenth Street in Washington.", "Mary was briefly involuntarily institutionalized for psychiatric disease ten years after her husband's assassination, but later retired to the home of her sister.", "She also complained of many physical symptoms during her adult life."]], ["Julia Taft Bayne", ["Julia Taft Bayne (March 4, 1845 \u2013 December 14, 1933) was an American author who wrote a memoir of the Lincoln White House entitled \"Tad Lincoln's Father\" (1931), based on her time visiting the household as a teenager with her younger brothers."]], ["Khalid al-Habib", ["Khalid al- Habib also believed to use the nom de guerre Khalid al Harbi is an Al- Qaeda leader who has overseen Al- Qaeda operations in Afghanistan.", "In 2005 it was reported that al- Habib died in a US missile strike on the Pakistani village of Damadola though it is unclear whether this is the case as Pakistani officials have claimed that no Al- Qaeda leaders died in the attack.", "al- Habib's nationality is not clear with sources claiming he may be Egyptian or Moroccan."]], ["Ali Rahuma", ["Ali Khalifa Rahuma( born May 16, 1982) is a Libyan football midfielder who's nationality is Libyan.", "He currently plays for Al- Ittihad, and is a member of the Libya national football team."]]]
supporting_facts: [["Tad Lincoln", 0], ["Mary Todd Lincoln", 0]]
evidences: [["Thomas \"Tad\" Lincoln", "mother", "Mary Todd Lincoln"], ["Mary Todd Lincoln", "country of citizenship", "United States"]]
answer: United States