In much of New England, Patriot's Day is celebrated today (Patriots' Day in Maine). The Boston Marathon will be run tomorrow, cognizant that two years ago, the Marathon was a target of terrorist bombings. Three people were killed and more than 260 were injured in the 2013 event. Chechen brothers Dzhokhar Tsarnaev and Tamerlan Tsarnaev were identified as the bombers, with Tamerlan being killed in the manhunt and Dzhokar being tried for the crime. He was found guilty earlier this month and awaits his fate in a Boston jail.

That's what Patriot's Day means to most people - that and perhaps the Red Sox playing a matinee to mark the day. In truth, April 19 is the anniversary of one of the most significant events in human history; the opening act of the American Revolution where colonists threw down the gauntlet to the most powerful country in the world.

Both Lexington and Concord are featuring re-enactments of the battles where the "shot heard 'round the world' was fired.

The National Park Service and various other groups have a full weekend full of activities planned in commemoration of Patriots' Day -- a day that recalls the events in the towns of Concord and Lexington that signified the start of the American Revolution. 

It was April 19, 1775 when British troops marched from Boston to Concord to seize and destroy munitions being stored there by the local militia. Just hours earlier the very first shot of the war was fired in Lexington when soldiers ordered militia gathered there to disperse. Eight colonists were killed and 10 others wounded in the initial skirmish. By the end of the day, however, militia -- mostly farmers with guns -- would have the British army on the run back to Boston. The American Revolution had begun. 

You can see a live re-enactment of that bloody battle this weekend at Minuteman National Historical Park. Minuteman companies from surrounding towns and living historians portraying British soldiers from the Revolution will engage in simulated battle as well as enabling visitors to get a glimpse of colonial life.

You can find the full schedule of events hosted by the National Park Service here. 

But if the smell of black powder and the sound of musket fire is what you're looking for, the "Battle Road: Returning to Lexington" event at 2 p.m. on Saturday is the event you want to be at. Hundreds of re-enactors will re-create the British retreat where militia attacked the troops at nearly every turn. From the description: "This event will involve musket firing and fast-paced battle action."

The best viewing opportunities will be from the Minuteman National Park Visitor Center at 250 North Great Road, Lincoln. But be sure to head over to the North Bridge in Concord, too. 

And if you're an early-riser, on Patriots' Day, April 20 this year, you can gather at the Lexington Green at 5:30 a.m. to see a re-enactment of the very first shots of the American Revolution.

The re-enactors will no doubt do a good job. They commit themselves to portraying their characters as realistically as possible.

What they can't do is re-enact the pride and courage of those Minute Men on Lexington Green who stood in defiance of British Major Pitcairn's arrogant call for the colonists to disperse. Nor can they duplicate the rage of Massachusetts militiamen who heard of the slaughter of 8 of their fellows at Lexington and headed for Concord to confront the British army.

Nor can we leave Paul Revere out of our reverie. His ride - immortalized in Longfellow's stylish, but historically uneven account - alerted patriots in Lexington to the danger, including the intelligence that the British were going to stop and arrest Sam Adams and John Hancock who were staying with friends in town.. But he never made it to Concord to warn the militia that the British were after the store of arms kept there., He was captured by a British picket around 2:00 AM. But his compatriot  Dr. Samuel Prescott, eluded the British and made it to Concord to spread the word. The British managed to find a couple of seige guns but the bulk of the arms remained safely hidden..

April 19 should be made a national holiday so that we can mark the moment in history when America roused itself to defend it's God-given rights. Independence may not have been on the minds of all patriots, but a significant number of Americans, inspired by the propaganda efforts of Sam Adams and others, knew what they were fighting for and the long odds against them.

Longfellow made the case in his poem:

You know the rest. In the books you have read
How the British Regulars fired and fled,---
How the farmers gave them ball for ball,
>From behind each fence and farmyard wall,
Chasing the redcoats down the lane,
Then crossing the fields to emerge again
Under the trees at the turn of the road,
And only pausing to fire and load.

So through the night rode Paul Revere;
And so through the night went his cry of alarm
To every Middlesex village and farm,---
A cry of defiance, and not of fear,
A voice in the darkness, a knock at the door,
And a word that shall echo for evermore!
For, borne on the night-wind of the Past,
Through all our history, to the last,
In the hour of darkness and peril and need,
The people will waken and listen to hear
The hurrying hoof-beats of that steed,
And the midnight message of Paul Revere.