Question: "A More Perfect Union" is the name of a speech delivered by then Senator and future President Barack Obama on which date, Obama was responding to a spike in the attention paid to controversial remarks made by the Reverend Jeremiah Wright, his former pastor and, until shortly before the speech, a participant in his campaign?

<P0-S0> The Jeremiah Wright controversy gained national attention in the United States, in March 2008 when ABC News, after reviewing dozens of U.S. Presidential candidate Barack Obama's pastor Jeremiah Wright's sermons, excerpted parts which were subject to intense media scrutiny. <P0-S1>  Wright is a retired senior pastor of Trinity United Church of Christ in Chicago and former pastor of President Obama. <P0-S2>  Obama denounced the statements in question, but critics continued to press the issue of his relationship with Wright. <P0-S3>  In response to this, he gave a speech titled "A More Perfect Union", in which he sought to place Wright's comments in a historical and sociological context. <P0-S4>  In the speech, Obama again denounced Wright's remarks, but did not disown him as a person. <P0-S5>  The controversy began to fade, but was renewed in late April when Wright made a series of media appearances, including an interview on "Bill Moyers Journal", a speech at the NAACP, and a speech at the National Press Club. <P0-S6>  After the last of these, Obama spoke more forcefully against his former pastor, saying that he was "outraged" and "saddened" by his behavior, and in May he resigned his membership in the church. <SEP> <P1-S0> Harris Llewellyn Wofford Jr. (born April 9, 1926) is an American attorney and Democratic Party politician who represented Pennsylvania in the United States Senate from 1991 to 1995. <P1-S1>  A noted advocate of national service and volunteering, Wofford was also the fifth president of Bryn Mawr College from 1970 to 1978, served as Chairman of the Pennsylvania Democratic Party in 1986, as Pennsylvania Secretary of Labor and Industry in the cabinet of Governor Robert P. Casey from 1987 to 1991 and was a surrogate for Barack Obama's 2008 presidential campaign. <P1-S2>  He introduced Obama in Philadelphia at the National Constitution Center before Obama's speech on race in America, "A More Perfect Union". <SEP> <P2-S0> Jeremiah Alvesta Wright Jr. (called Jerry; born September 22, 1941) is a pastor emeritus of Trinity United Church of Christ in Chicago, with a congregation exceeding 6,000. <P2-S1>  In early 2008, Wright retired after 36 years as the Senior Pastor and no longer has daily responsibilities at the church. <P2-S2>  Following retirement, Wright's beliefs and preaching were scrutinized when segments of his sermons were publicized in connection with the presidential campaign of Barack Obama. <P2-S3>  Obama addressed the issues raised by the Wright controversy in his speech entitled "A More Perfect Union". <SEP> <P3-S0> "A More Perfect Union" is the name of a speech delivered by then Senator and future President Barack Obama on March 18, 2008 in the course of the contest for the 2008 Democratic Party presidential nomination. <P3-S1>  Speaking before an audience at the National Constitution Center in Philadelphia, Pennsylvania, Obama was responding to a spike in the attention paid to controversial remarks made by the Reverend Jeremiah Wright, his former pastor and, until shortly before the speech, a participant in his campaign. <P3-S2>  Obama framed his response in terms of the broader issue of race in the United States. <P3-S3>  The speech's title was taken from the Preamble to the United States Constitution.