Short answers, pulled from the story.
Maxime Faget sketched the Little Joe rocket design at NASA's Langley Research Center in 1958. He named the project based on a four-in-craps slang term after observing four large fins on his drawings.
NASA managers set the Little Joe booster cost at $200,000 per unit to save money compared to other options. Atlas rockets required approximately US$2.5 million per launch while Redstone vehicles cost about $1 million each during early 1958 reviews.
Sam flew aboard Little Joe 2 on the 4th of December 1959 as a rhesus macaque. The mission reached an altitude of 53 miles or 85 kilometers before recovery by SE of Wallops Island.
North American Aviation won the contract for seven booster airframes on the 29th of December 1958. The company began work immediately in Downey, California to manufacture the units.
Castor rockets burned for 37 seconds while generating 58,200 pounds of thrust. Maximum design thrust for the entire cluster reached almost 230,000 pounds or 1,020 kilonewtons.
The third test with a production spacecraft succeeded on the 28th of April 1961 to conclude the program. This flight followed multiple electrical malfunctions that required engineering fixes throughout 1959 and 1960.