Truman sent advisors in 1950, we had advisors numbering in the hundreds from Truman, to Ike, to Ike again, and then to JFK, and then boom, JFK kills Diem and sends in 16,000 troops.
JFK also emptied the mental hospitals which eventually became the American homeless.
He unionized federal employees.
Signed the first affirmative action law.
He ran on chain migration and tried to pass his immigration dream which eventually passed as his 1965 Immigration bill.
The President’s Commission on the Status of Women endorsed workplace equality, child care facilities for working women, paid maternity leave, better Social Security benefits for widows, and equal pay for comparable work.
The War on Poverty (an idea he had rolled out during the campaign) sought to alleviate penury, especially among the elderly, by pushing for Medicare and expanded Social Security benefits.
He used federal troops to ensure the enrollment of black students at the universities of Mississippi and Alabama; his administration implemented the first “affirmative action” program for government employees and contractors.
He sent over 16,000 troops to Vietnam.
Kennedy endorsed the United Nations as “our last best hope,”
He withdrew for the Cuban rebels the sufficient air cover they needed at the Bay of Pigs.
For sure JFK and many presidents have made mistakes. But the fact remains that it was under LBJ & Nixon that the central government so greatly expanded at the expense of state & local government...and the private sector.