Concord Massachussetts is a historic town in the USA. It is home of the minute men who fought off the British leading to the independence of the United States of America in 1775. 
 
There are many terms that the Minute men used which are still used today in modern American English. Here is a sample taken from the Concord Magazine.

A musket was usually accomplished and paid for in three parts - lock (firing mechanism), stock (wood), barrel (metal tube). Once completed the item as a whole was given to its owner. Today when one obtains an item with all its parts, it is owned “lock, stock and barrel”.
 
If militia man Thaddeus Blood placed his musket in the safety position (half-cocked) then entered battle, he had better remember to advance to full-cock or the weapon would not fire and he would be in trouble. A person “going off half cocked” now means not successful due to lack of preparation and forethought.

Nathan Stowe might prime his weapon (small measure of powder in the pan), load the main charge to the barrel, fire and only have the priming powder explode. This was known as a “flash in the pan” or misfire. Today, the term means a sudden brief success not likely to be repeated or followed by a greater success. 
 
Thomas Munroe, tavern keep, might use chalk to mark upon his wall the bill of a patron who wished to pay at a later time. This was a reminder to collect owed money. Something is “chalked up” to experience in our world meaning that while unfortunate, it is not regretted but an attempt will be made to insure it does not happen again.
 
Grog was a cheap 18th Century drink of rum and water invented by a ship’s captain to water down sailor’s daily liquor ration in hopes of ending drunken brawls. Today one who consumes too much spirits may appear “groggy” or mildly intoxicated.
 
Keeper Ephraim Jones might yell to rowdy patrons to “mind their p’s and q’s” (pints and quarts of drink) and today the term still refers to watching ones manners and conduct; behaving properly. 
 
Today, a “rule of thumb” is a way to accomplish a task based on experience rather than theory or careful calculation. A colonial brewer (without a thermometer) would dip his thumb into a mixture to determine when the liquid was the right temperature to add the yeast.

If we receive unexpected good fortune (usually money) it is called “a wind fall”. For Jonas Bateman in the 1770s it meant that trees or limbs were blown down and easily obtained for firewood.

Purchase Brown, 1770s farmer, would “ear mark” his animals with a distinctive brand to denote ownership or purpose.
 
Citizens would gather annually on muster day to watch the militia drill, enjoy food and drink, socialize and have a fun time. They had a “field day”.
 
When John Buttrick, Jr. retired for the night, he probably would sleep on bedding of straw and thus in today’s usage he would “hit the hay”.
 
Meliscent Barrett might have the rope supports between the wooden sides of her bed frame tightened (no metal springs) to insure a good night’s sleep. As today, she would be requested to “sleep tight”.

When next you hear a modern idiom, ask if it has origins in the 18th Century and might have been used in 1775 Concord.