Probably best known for 'Mrs Frisby and the Rats of NIMN', Robert Leslie Conley was born in New York. Known as Robert C. O'Brien began to write children's stories in the 60's when his family moved closer to Washington DC.
'Mrs Frisby and the Rats of NIMN' was written in 1971 and won the Newbery Medal in 1972. With well developed characters, themes of courage, morality and the real meaning of heroism, and clever plotting that gradually brings two story lines together, it offers a great read. I devoured this as a child and enjoyed it again as a parent, proving it stands the test of time.
'Z for Zachariah' was published posthumously in 1974. A post-apocalyptic, science fiction novel, this is a gripping, compelling read which is thought provoking and tense. Although originally aimed at adults by O'Brien, it sits well with the current young adult novels on the market.