Question: The Clark Memorandum was written by the undersecretary of which man, who was the 30th President of the United States?

Context articles: John F. Kennedy presidential campaign, 1960
House Grey Memorandum
Wallace McCamant
OMEGA Memorandum
Task Force on Childhood Obesity
Sharm El Sheikh Memorandum
First inauguration of Calvin Coolidge
Presidential memorandum
Calvin Coolidge
Clark Memorandum

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.
The House-Grey Memorandum was a memorandum prepared by President of the United States Woodrow Wilson's diplomatic emissary to Europe, "Colonel" Edward M. House, and the British Foreign Secretary, Sir Edward Grey.
Wallace McCamant (September 22, 1867 – December 17, 1944) was an American jurist in Oregon.
 A Pennsylvania native, he served as the 46th Associate Justice of the Oregon Supreme Court from 1917 to 1918.
 Later he served briefly on the United States Court of Appeals for the Ninth Circuit.
 As a delegate to the Republican National Convention in 1920, McCamant surprised the GOP leadership by placing the name of Calvin Coolidge into nomination for Vice-President.
 Coolidge would become the 30th President of the United States upon the death of President Harding in 1923.
The 'OMEGA' memorandum of March 28, 1956, was a secret United States informal policy memorandum drafted by Secretary of State John Foster Dulles for President Dwight D. Eisenhower.
 The goal was to reduce the influence in the Middle East of Egypt's President Gamal Abdel Nasser because he seemed to be leaning in favor of the Soviet Union, and he failed to provide the leadership that Dulles and Eisenhower had desired towards settling the Arab-Israeli conflict.
 The memoranda contained possible options but it was never formally endorsed or put into effect.
The Childhood Obesity Task Force is a United States Government task force charged with reducing childhood obesity in the United States.
 It was founded on February 9, 2010 by the Obama Administration through a Presidential Memorandum, announcing the establishment of a Task Force on Childhood Obesity.
 The Task Force aims to develop a plan to reduce childhood obesity.
 In the announcement, President Barack Obama highlighted the statistics on childhood obesity in the United States and outlined the steps that this new task force would be taking to end childhood obesity.
 Section 1 of the Memorandum states:
The Sharm El Sheikh Memorandum, full name: The Sharm El Sheikh Memorandum on Implementation Timeline of Outstanding Commitments of Agreements Signed and the Resumption of Permanent Status Negotiations was a memorandum signed on September 4, 1999 by Prime Minister of Israel Ehud Barak and PLO Chairman Yasser Arafat at Sharm el Sheikh in Egypt, overseen by the United States represented by Secretary of State Madeleine Albright.
 The memorandum was witnessed and co-signed by President Hosni Mubarak of Egypt and King Abdullah of Jordan.
The first inauguration of Calvin Coolidge as the 30th President of the United States was held on Friday, August 3, 1923 at the Coolidge Homestead in Plymouth Notch, Vermont, following the death of President Warren G. Harding the previous evening.
 The inauguration marked the commencement of the first term (a partial term of ) of Calvin Coolidge as President.
 The presidential oath of office was administered to the new president by his father, John Calvin Coolidge Sr., who was a Vermont notary public and justice of the peace.
A presidential memorandum is a type of executive action issued by the President of the United States to manage and govern the actions, practices, and policies of the various departments and agencies found under the executive branch of the United States government.
 It has the force of law and is usually used to delegate tasks, direct specific government agencies to do something, or to start a regulatory process.
 There are three types of presidential memoranda: presidential determination or presidential finding, memorandum of disapproval, and hortatory memorandum.
John Calvin Coolidge Jr. ( ; July 4, 1872 – January 5, 1933) was the 30th President of the United States (1923–29).
 A Republican lawyer from Vermont, Coolidge worked his way up the ladder of Massachusetts state politics, eventually becoming governor of that state.
 His response to the Boston Police Strike of 1919 thrust him into the national spotlight and gave him a reputation as a man of decisive action.
 Soon after, he was elected as the 29th vice president in 1920 and succeeded to the presidency upon the sudden death of Warren G. Harding in 1923.
 Elected in his own right in 1924, he gained a reputation as a small-government conservative, and also as a man who said very little, although having a rather dry sense of humor.
The Clark Memorandum on the Monroe Doctrine or Clark Memorandum, written on December 17, 1928 by Calvin Coolidge's undersecretary of state J. Reuben Clark, concerned the United States' use of military force to intervene in Latin American nations.
 This memorandum was officially released in 1930 by the Herbert Hoover administration.