WASHINGTON — President Joe Biden exhorted Congress Tuesday night to work with him to “finish the job” of rebuilding the economy and uniting the nation as he delivered a State of the Union address aimed at reassuring a country beset by pessimism and fraught political divisions. In his 73-minute speech, Biden sought to portray a nation dramatically improved from the one he took charge of two years ago: from a reeling economy to one prosperous with new jobs; from a crippled, pandemic-weary nation to one that has now reopened, and a democracy that has survived its biggest test since the Civil War. “Folks, the story of America is a story of progress and resilience.