Question: What was the book The Conservative Case for Trump written by Phyllis Schlafly best known for?
Context: 1964 is a documentary film produced by Insignia Films for the American Experience series about political, social and cultural events in the United States for the calendar year 1964.  It is based partly on Jon Margolis book "The Last Innocent Year: America in 1964."  The documentary depicts the year 1964 as significant and epic in that following the assassination of President John F. Kennedy in late 1963, 1964, as a presidential election year, becomes a departure point for American history, that the U.S. is still affected by.  It is also the year of the British Invasion led by the Beatles, when Cassius Clay fights Sonny Liston for the World Heavyweight Championship, Betty Friedan book, "The Feminine Mystique", is published, and Republican activist, Phyllis Schlafly's book, "A Choice, Not an Echo", is published.  It is also the year of Freedom Summer, an initiative by the Student Nonviolent Coordinating Committee to register African-Americans in Mississippi, the subsequent murders of Chaney, Goodman, and Schwerner, three CORE activists, in Mississippi by white supremacists that created a national sensation, and the Harlem riot of 1964, culminating in the Berkeley Free Speech Movement at the University of California at Berkeley.  A recurrent theme of the film is its departure as a presidential election year, with President Lyndon B. Johnson running as the expected Democratic Party nominee and the nomination of U.S. Senator Barry Goldwater selected through a grassroots campaign for the Republican nomination for President of the United States, that defines the future divisions of the US political party competition. Eagle Forum is a conservative interest group in the United States founded by Phyllis Schlafly in 1972 and is the parent organization that also includes the Eagle Forum Education and Legal Defense Fund and the Eagle Forum PAC.  The Eagle Forum has been primarily focused on social issues; it describes itself as pro-family and reports membership of 80,000.  Others have described it as socially conservative and anti-feminist. A Choice Not an Echo is a 1964 book by conservative icon Phyllis Schlafly.  Schlafly published the book herself, which has sold more than three million copies. The Conservative Case for Trump is a 2016 book by Phyllis Schlafly, a movement conservative best known for helping to defeat the Equal Rights Amendment in the 1970s.  The book was published in September 2016, following the nomination of Donald Trump for President of the United States, and explains in detail Schlafly's rationale for branding Trump as a serious conservative and (in her opinion) a better candidate than Hillary Clinton. Women in conservatism in the United States have advocated for social, political, economic, and cultural conservative policies since Anti-suffragism.  Leading conservative women such as Phyllis Schlafly have expressed that women should embrace their privileged essential nature.  This thread of belief can be traced through the Anti-Suffrage movement, the Red Scare, and the Reagan Era, and is still very much present today, especially in several notable conservative women's organizations such as Concerned Women for America and the Independent Women's Forum. Conservapedia is an English-language wiki encyclopedia project written from an American conservative point of view.  The website was started in 2006 by American homeschool teacher and attorney Andrew Schlafly, son of conservative activist Phyllis Schlafly, to counter what he perceived as a liberal bias present in Wikipedia.  It uses editorials and a wiki-based system to generate content. Julius Krein (born 1986) is an American conservative political writer and editor best known as the founder of the journal "American Affairs".  Krein launched the pro-Donald Trump journal in February 2017 in a bid "to give the Trump movement some intellectual heft."  Six months later, however, Krein publicly withdrew his support for Trump, writing that he regretted his prior support of him as president. Phyllis Natalie Tickle (née Alexander; March 12, 1934 – September 22, 2015) was an American author and lecturer whose work focuses on spirituality and religion issues.  After serving as a teacher, professor, and academic dean, Tickle entered the publishing industry, serving as the founding editor of the religion department at "Publishers Weekly", before then becoming a popular writer.  She is well known as a leading voice in the emergence church movement.  She is perhaps best known for "The Divine Hours" series of books, published by Doubleday Press, and her book "The Great Emergence- How Christianity Is Changing and Why".  Tickle was a member of the Episcopal Church, where she was licensed as both a lector and a lay eucharistic minister.  She has been widely quoted by many media outlets, including "Newsweek", "Time", "Life", "The New York Times", "USA Today", CNN, C-SPAN, PBS, The History Channel, the BBC and VOA.  It has been said that "Over the past generation, no one has written more deeply and spoken more widely about the contours of American faith and spirituality than Phyllis Tickle." Phyllis McAlpin Schlafly ( ; née Stewart; August 15, 1924 – September 5, 2016) was an American constitutional lawyer and conservative activist.  She was known for her staunchly conservative social and political views, her opposition to feminism and abortion, and her successful campaign against the ratification of the Equal Rights Amendment to the U.S. Constitution.  Her 1964 book, "A Choice Not an Echo", a polemic push-back against Republican leader Nelson Rockefeller, sold more than three million copies.  She co-authored books on national defense and was highly critical of arms control agreements with the former Soviet Union.  Schlafly founded the conservative interest group Eagle Forum in 1972 and remained its chairperson and CEO until her death. Andrew Layton "Andy" Schlafly ( ; born April 27, 1961) is an American lawyer and Christian conservative activist, and the founder and owner of the wiki Conservapedia.  He is the son of the conservative activist and lawyer Phyllis Schlafly.
Answer: helping to defeat the Equal Rights Amendment in the 1970s