Question: What ethnic group was the painter of the wife of the 36th President of the United States part of?

Context paragraphs:
36th Operations Group: The 36th Operations Group (36 OG) is the operational component of the 36th Wing, assigned to the United States Air Force Pacific Air Forces.  The group is stationed at Andersen Air Force Base, Guam.

Tiv people: Tiv (or Tivi) is an ethno-linguistic group or ethnic nation in West Africa.  The group constitutes approximately 7% of Nigeria's total population, and number about 3.5 million individuals throughout Nigeria and Cameroon.  The Tiv are the 4th largest ethnic group in Nigeria.  The Tiv language is spoken by about 2.2 million people in Nigeria (as of 1991), with a few speakers in Cameroon.  Most of the language's Nigerian speakers are found in Benue State of Nigeria.  The language is also widely spoken in the Nigerian States of Plateau, Taraba, Nasarawa and Cross River, as well as the FCT Abuja.  It is part of the Southern Bantoid Tivoid family, a branch of Benue–Congo and ultimately of the Niger–Congo phylum.  In precolonial times, the Fulani ethnic group referred to the Tiv as "Munchi", a term not accepted by Tiv people.  They depend on agricultural produce for commerce and life.

Presidency of Lyndon B. Johnson: The presidency of Lyndon B. Johnson began on November 22, 1963, when Johnson became the 36th President of the United States upon the assassination of President John F. Kennedy, and ended on January 20, 1969.  He had been Vice President of the United States for days when he succeeded to the presidency.  A Democrat, he ran for and won a full four-year term in the 1964 election, winning by a landslide over Republican opponent Arizona Senator Barry Goldwater.  Following the 1968 presidential election he was succeed by Republican Richard Nixon.

Richard Nixon: Richard Milhous Nixon (January 9, 1913 – April 22, 1994) was the 37th President of the United States from 1969 until 1974, when he resigned from office, the only U.S. president to do so.  He had previously served as the 36th Vice President of the United States from 1953 to 1961, and prior to that as a U.S. Representative and also Senator from California.

Lyndon B. Johnson: Lyndon Baines Johnson ( ; August 27, 1908January 22, 1973), often referred to as LBJ, was an American politician who served as the 36th President of the United States from 1963 to 1969, assuming the office after serving as the 37th Vice President of the United States from 1961 to 1963.  A Democrat from Texas, he also served as a United States Representative and as the Majority Leader in the United States Senate.  Johnson is one of only four people who have served in all four federal elected positions.

Electoral history of Lyndon B. Johnson: Electoral history of Lyndon B. Johnson, the 36th President of the United States (1963–1969), 37th Vice President of the United States (1961–1963); United States Senator (1949–1961) and United States Representative (1937–1949) from Texas.

Electoral history of Richard Nixon: Electoral history of Richard Nixon, 37th President of the United States (1969–1974), 36th Vice President of the United States (1953–1961); United States Senator (1950–1953) and United States Representative (1947–1950) from California.

Elizabeth Shoumatoff: Elizabeth Shoumatoff (Russian: Елизавета Николаевна Шуматова , "née" Avinoff) (October 6, 1888 – November 30, 1980) was a Russian-American painter who was best known for painting the Unfinished Portrait of Franklin D. Roosevelt.  Other paintings included Lyndon B. Johnson and Lady Bird Johnson.

Lady Bird Johnson: Claudia Alta "Lady Bird" Johnson (née Taylor; December 22, 1912 – July 11, 2007) was First Lady of the United States (1963–69), as the wife of the 36th President of the United States, Lyndon B. Johnson.

USS Lyndon B. Johnson: USS "Lyndon B. Johnson" (DDG-1002) will be the third and final "Zumwalt"-class destroyer built for the United States Navy.  The contract to build her was awarded to Bath Iron Works located in Bath, Maine, on 15 September 2011.  The award, along with funds for the construction of USS "Michael Monsoor" , was worth US$1.826 billion.  On 16 April 2012, Secretary of the Navy Ray Mabus announced the ship would be named "Lyndon B. Johnson" in honor of Lyndon B. Johnson, who served as the 36th President of the United States from 1963 to 1969.  Johnson served in the Navy during World War II, when he was awarded the Silver Star, and ultimately reached the U.S. Naval Reserve rank of commander.  DDG-1002 is the 34th ship named by the Navy after a U.S. president.

Supporting paragraphs: Elizabeth Shoumatoff Lady Bird Johnson
Answer: Russian-American