Here is another review about The Birth of A Nation from TV Guide
This notoriously problematic melodrama is the first true screen epic and arguably the most important motion picture ever made. Virtually overnight, THE BIRTH OF A NATION compelled cultural gatekeepers to reckon with cinema, not as a mere arcade novelty, but as a uniquely vigorous, wholly credible art form. As the film unfolds, with a majestic assurance undiminished by time, the viewer can practically see director D.W. Griffith inventing the narrative conventions, editing style, and production techniques that have dominated Hollywood cinema ever since.
That this undeniable masterpiece is also a wholesale endorsement of white supremacy is an irony that may reveal more about the American past than some of us want to know. Griffith's naive, deeply held, and unquestionably vicious notions of race and history are on full display here. Jim Crow is explicitly endorsed; slavery is romanticized; the Ku Klux Klan is glorified; lynching is condoned; and blacks are represented as simple-minded beasts driven primarily by lust and envy (another respect in which Griffith set the tone for many later Hollywood movies). On viewing the film at a special White House screening, President Woodrow Wilson (whose racial views weren't much different from Griffith's) famously observed that THE BIRTH OF A NATION is "like history written in lightning." Far from it: it's more like ideology conveyed--unforgettably--in lightning, and the rhetorical power of this new medium was not lost on manipulators of opinion worldwide.
Based on two popular novels and a stage play by ultraracist ideologue Thomas Dixon, Jr., THE BIRTH OF A NATION aims to bring a tragic period of American history to life by tracing the interconnected fortunes of two fictional families. In the antebellum South, the Camerons of Piedmont, South Carolina, play host to visiting friends from Pennsylvania, the Stonemans, whose stern patriarch (Ralph Lewis) is the leading abolitionist in the House of Representatives. Romance blossoms between his daughter Elsie (Lillian Gish) and Ben Cameron (Henry B. Walthall), but when war breaks out, the Cameron boys enlist with the Confederates and the Stoneman sons sign on with the Union forces. Battles rage as history unfolds on the screen--the burning of Atlanta, Sherman's March, the surrender at Appomattox, and Lincoln's assassination are rendered in epic style (Griffith and cameraman Billy Bitzer modeled many of the historical tableaux on period photographs from Matthew Brady's studio; the director believed that film could quite literally recreate, or "picturize," historical reality).
In the film's second half, Griffith's warped view of the Reconstruction period--complete with venal carpetbaggers and their simian black stooges--forms the backdrop for a myth of national rebirth involving the rise of the Ku Klux Klan. After Flora Cameron (Mae Marsh) dies resisting a rape attempt at the hands of "renegade Negro" Gus (white actor Walter Long in blackface), Ben, now known as The Little Colonel, organizes the Klan, thus countering the machinations of scheming mulatto Silas Lynch (George Siegmann) and restoring stability--i.e., a white supremacist social order--to the American South.
Although Griffith saw his film as a vivid history lesson, it is probably best understood as domestic melodrama played out on a national scale. The American nation is represented as a family in crisis, torn apart by the advent of a menacing other--the black race--and nearly destroyed after the death of its benevolent patriarch, Abraham Lincoln. Conversely, the domestic story line is developed so as to mirror historical events and social currents--the final union of Ben and Elsie, for instance, is meant to symbolize the reconstitution of a divided nation. Griffith's narrative technique and symbolic method are seminal, and no one who hopes to understand how movies reflect and construct ideology can afford to ignore THE BIRTH OF A NATION.
Griffith was a great admirer of Dixon's play, The Clansman; the director's own wife, Linda Arvidson Griffith, had starred in a cinema adaptation made by the Kinemacolor Company in 1909 (the underexposed footage didn't print properly, so the picture was shelved). Griffith's cowriter Frank E. Woods, who had written the earlier screen adaptation, suggested the project to the director. Brought in on a budget of about $100,000, this remarkable picture set a box-office record unsurpassed for silent films. By 1931, it had returned more than $18 million for Epoch, a company created especially for the production by Griffith and Harry E. Aitken, whose Triangle Film Corporation had recently lured the director away from American Biograph. (Violence.)