Listen my children and you shall hear
Of the midnight ride of Paul Revere,
On the Eighteenth of April, in Seventy-five;
Hardly a man is now alive
Who remembers that famous day and year.
So wrote Henry Wadsworth Longfellow in 1860. Paul Revere really did ride across the Massachusetts countryside on the night of April 18, 1775, part of a large intelligence network, warning of advancing British troops. The Battles of Concord and Lexington, fought the next day, were a response to a British mission to seize the militia’s weapons–particularly their artillery. 
News of the fighting began to appear in Maryland newspapers about a week later. On April 27, the Maryland Gazette in Annapolis published a report from the day of the battles:
this morning before break of day, a [British] brigade consisting of 1,200 men landed…and marched to Lexington, where they found a company of our colony militia in arms, upon whom they fired without provocation, and killed six men, and wounded four others.
A second dispatch followed:
the contest between the first brigade [of British troops] that marched to Concord, was still continuing this morning at the town of Lexington, to which said brigade had retreated, [and] another brigade had…landed with a quantity of artillery…The provincials were determined to prevent the two brigades from joining their strength if possible, and remain in great need of succour. 
Reaction to the news was swift. Maryland’s Revolutionary government had issued a call for militia volunteers at the end of 1774, which had been enthusiastically answered. With the memories of Lexington and Concord fresh in the minds of many Marylanders, the spring and summer of 1775 saw large-scale military build-up, not only new enlistments but an entire new command structure. In June, two companies of riflemen from Western Maryland were formed and traveled to Boston to aid the Revolutionary cause. 
The militia build-up was not a symbolic move, either. There was genuine fear that British troops would be sent to Maryland. In Boston, revolutionaries had dumped a cargo of tea that violated the boycott of British goods; by the summer of 1775, the Marylanders had burned two ships. If the Boston Tea Party justified military occupation and the closing of the port, what would be Maryland’s fate? 
In the end, no British troops came to Maryland, and no battles took place there during the Revolution. However, the steps the state took to arm itself in 1775 left it ready to answer Congress’ call for troops in 1776, when the First Maryland Regiment was created. But first came Lexington and Concord, and what Ralph Waldo Emerson described:
By the rude bridge that arched the flood,
Their flag to April’s breeze unfurled,
Here once the embattled farmers stood
And fired the shot heard round the world. 
3. David Curtis Skaggs, Roots of Maryland Democracy 1753-1776 (Westport CT: Greenwood Press, 1973), 156-158. To learn more about the Maryland riflemen, see the Diary of Daniel McCurtin, one of the soldiers.
4. Skaggs, 156-158. The Peggy Stewart was burned in October 1774–Anthony Stewart, the ship’s owner–nearly had his house burned down as well, and the Totness was burned in July 1775. See Skaggs 143-149. Mordacai Gist lead one of the more militant groups at the burning of the Peggy Stewart.
5. “Concord Hymn,” Ralph Waldo Emerson, 1837. http://www.poetryfoundation.org/poem/175140.