The United States Army was born in 1775, when the Continental Congress approved the raising of a Continental Army following the outbreak of the American Revolution.  But there are units serving the U.S. Armed Forces today that were fighting and protecting long before that.  None are older than the handful of regiments that got their start right here in Massachusetts.

At celebrations this week at Hanscom Air Force Base, the Pentagon, and at Army and Air Force National Guard bases across the country, the directive came down: Let Us Eat Cake.

"We find the oldest retired national guardsman, and we bring up the youngest national guardsman and they cut the cake," said Len Kontratiuk, Director of Historical Services for the Massachusetts National Guard.  "That’s kind of a military tradition – with a sword."

The cake Kontratiuk referred to was a birthday cake, celebrating the National Guard's 380th.  It got its start on Dec. 13, way back in 1636, when the Massachusetts Bay colony, by act of the legislature, organized its various town militias into three regiments, then a fairly novel idea.

"And so the idea was let's have three regiments, called the North, South and East," said Kontratiuk.  "We’ll have a colonel, a staff.  The town captains report to the colonel, the colonel reports to the governor."

Those three original regiments, comprised of citizen soldiers, have never gone out of service.

You might have heard of the exploits of that South regiment, today the 101st Field Artillery Regiment, on the very first Patriots Day.      

"Sam Adams was a member of the Boston regiment, as it was called in 1775," said Kontratiuk. "Paul Revere was a member, William Dawes was a member of this regiment. They had to all possess weapons and go to drill several times a year."

The famed preparedness of the minutemen of the Massachusetts militia carried forward into the next century, when the U.S. was again hurtling toward war, this time with itself.

"Get this, they were the first regiment in the north to mobilize, to deploy and to shed blood in the Civil War," said Kontratiuk. "The Governor got a telegram on April 15, 1861, they were out the door April 17. Two days later. We can’t do that today. President Lincoln actually greeted them and thanked them personally for coming."

They would go on to fight at Gettysburg, Antietam and Bull Run among other crucial Civil War battles.

As we walked through the Museum and Library, Kontratiuk explained to me that it was during the lead-up to World War I that the Massachusetts state militia, and those of other states, were reorganized under a new banner: The National Guard, and given a unique dual duty – to serve and protect their state and the country.

"National Guard is different from the Army because they are not full time," explained Kontratiuk. "They’re different from the Army reserve because they have two Commanders-in-Chief, the President, if called by the President, or the Governor if called by the Governor."

And called on by Presidents, the Massachusetts National Guard has been. By World War I, all units of the Massachusetts National Guard, including those original regiments, comprised the U.S. Army’s 26th Division.

"The 26th Division, as a group, they were the first full U.S. Army division to deploy to France in World War I," said Kontratiuk. "You would think it would be the regular Army. This National Guard regiment was first."

The 26th, known as the Yankee Division, would also serve with distinction during World War II, including at Normandy and Guadalcanal.

"That’s why Route 128 is officially the Yankee Division Highway," explained Kontratiuk. "Because of all of its exploits in Word War I and World War II."

Today, some 8,000 citizen soldiers serve in more than 100 National Guard units in over 40 Bay State communities. In recent years, they’ve been mobilized by the governor to aid with coastal floods and the epic winter of 2015. And every one of those original three regiments have deployed to the Middle East.

"Massachusetts units have their own unique characteristics," said Kontratiuk. "The soldiers in these regiments are very proud of their service; that it goes back to 1636. Not only are we talking about historic units but we’re talking about units that created American military history."

Edgar B. Herwick III runs WGBH’s Curiosity Desk. If you have a tale of hidden Massachusetts history to share, email him at curiositydesk@wgbh.org.