Dallas ( CNN ) -- Five decades after it served as the backdrop for a nation 's grief and disbelief , Dallas ' Dealey Plaza took center stage once again Friday as Americans commemorated the 50th anniversary of President John F. Kennedy 's assassination . `` A new era dawned and another waned a half century ago when hope and hatred collided right here in Dallas , '' Dallas Mayor Mike Rawlings said in his remarks commemorating Kennedy 's death . Rawlings then read the final words of the speech Kennedy was to deliver that day . That was followed by a moment of silence at 12:30 p.m. , the time Kennedy was shot a few feet from where Rawlings spoke . Bells tolled , and after a brief pause , cadets from the Naval Academy sang `` America the Beautiful . '' Historian David McCullough read excerpts from famous Kennedy speeches . Some 5,000 invited guests were expected to attend the commemorative events , which was bookended by bagpipers -- a JFK favorite -- playing under a spitting gray sky . The tightly choreographed and secured event was the culmination of a series of commemorations Friday , including wreath-laying events in Kennedy 's home town of Boston and at his Arlington National Cemetery gravesite . In Washington , where flags flew at half-staff over the Capitol and White House , Kennedy 's last living sibling , Jean Kennedy Smith , participated in the Arlington wreath-laying . Earlier , Attorney General Eric Holder visited the gravesite . And in the House of Representatives , where Kennedy served from 1947 to 1953 , the Rev . John Robert Skeldon of Fort Worth , Texas , reminded lawmakers in his opening prayers that `` in commemorating such a one whose life and presidency were cut short , we do so not to sow in tears , as the psalmist says , but rather to reap with shouts of joy . '' `` Help us , Lord God , to make the late President 's inaugural vision our own so that together as fellow Americans we may 'ask not what our country can do for us , but rather what we can do for our country , ' '' Skeldon prayed , invoking Kennedy 's famous words . The Dallas event was designed to be a delicate balancing act of honoring Kennedy 's memory without sensationalizing his murder , and to help the city throw off its reputation as `` the city that killed Kennedy . '' It opened with a video from an organizer speaking of that goal , and continued in Rawlings remarks , which keyed off Kennedy 's call for the United States to embrace and conquer a `` New Frontier '' of challenges . The mayor spoke of a Dallas that took up the mantle of Kennedy 's challenge of American betterment and transformed itself with a `` sense of industry born of tragedy '' into a city that he hopes would make the president proud . `` He and our city will forever be linked , in tragedy , yes , '' Rawlings said . `` But out of that tragedy , an opportunity was granted to us : the chance to learn how to face the future when it 's the darkest and most uncertain , how to hold high the torch even when the flame flickers and threatens to go out . '' Boy who witnessed JFK assassination recalls the day . JFK assassination a collective memory for American children . A new JFK monument also was unveiled , in the infamous section of land known as the `` grassy knoll . '' The inscription on the monument is the final paragraph of the speech JFK intended to deliver at the Dallas Trade Mart on November 22 , 1963 : . `` We in this country , in this generation , are -- - by destiny rather than choice -- - the watchmen on the walls of world freedom . We ask , therefore , that we may be worthy of our power and responsibility , that we may exercise our strength with wisdom and restraint , and that we may achieve in our time and for all time the ancient vision of `` peace on earth , good will toward men . '' That must always be our goal , and the righteousness of our cause must always underlie our strength . For as was written long ago , `` except the Lord keep the city , the watchman waketh but in vain . '' Is there more to the JFK assassination ? Other Dallas events . Conspiracy theorists , who have typically gathered on the plaza on each anniversary of Kennedy 's assassination , were barred from the plaza . Instead , The Dallas Morning News reported , the group planned to hold an event at the nearby JFK memorial , and then move to Dealey Plaza after the main event was over . Demonstrators gathered at Dealey Plaza on Thursday , and many chanted : `` No more lies . No more lies . '' The remarkable Sixth Floor Museum , which chronicles the Kennedy assassination , was set to open from 3 to 8 p.m. CT. Parkland Hospital , where Kennedy died , planned a brief morning ceremony , where the flag will be lowered to half-staff . Also in Dallas on Friday , a candlelight vigil for J.D . Tippit was set for 6 p.m. at the site where the 39-year-old Dallas police officer was shot . `` I think the remembrance of him calls attention to all of the officers killed in the line of duty . We should remember those who have given their lives for our city , '' Marie Tippit , who had been married to the officer for 17 years , told the Los Angeles Times this week . She told the paper she will also attend the ceremony at Dealey Plaza . 5 things you might not know about JFK 's assassination . Finally , the Texas Theatre , where Lee Harvey Oswald was apprehended by police , was to screen part of the movie `` War Is Hell , '' the film that was showing when Oswald slipped into the audience without paying . Commemorations elsewhere . 50 years later , Jackie Kennedy 's pink suit locked away from view . The John F. Kennedy Presidential Library and Museum in Boston asked visitors to gather to watch a video musical tribute to the President that includes James Taylor . A moment of silence was held at 2 p.m . ET , the time when a doctor approximated Kennedy died . Moments of silence were also planned at various other locations around the nation . And online , a handful of Twitter accounts focused on recreating Kennedy 's movements that fateful day , culminating in breaking accounts of the aftermath of the shooting . CNN 's Ed Lavendera and John King reported from Dallas ; Michael Pearson reported and wrote from Atlanta ; CNN 's Steve Almasy also contributed to this report .
NEW : ` ` He and our city will forever be linked , '' the mayor says . Mike Rawlings says ` ` hope and tragedy collided '' in Dallas 50 years ago . Moment of silence , bells , a moment 50 years ago Kennedy was assassinated . Stone laid in Dallas ; House prayer invokes Kennedy 's memory .