"The Private Lives of Public Figures: The 19th Century Family Print," a new show at the Smithsonian's National Portrait Gallery through April 13, 1986, gives a small but enticing glimpse of the period's ideas about "Home Sweet Home."

In the 18th century, the public idealized romantic heroes. When people bought engravings and prints of their favorites, they expected the subject to be astride a white horse, waving a sword at the infidels, leading loyal troops to victory or attending to great matters of state in arched halls. If dead, the heroes were to be borne on the four winds to heaven, attended by angels, seated at the right hand of God.

By the second half of the 19th century, the view of the hero had changed. The bitter War Between the States had pitted brother against brother. A period of relative peace and prosperity followed, but it was broken by a series of assassinations and official scandals. To establish that a government official or a general was a suitable candidate for canonization became harder.

Factories and large stores took men away from the family farms and mom-and-pop stores where husbands, wives, children and grandparents worked together. Work and home became two separate places.

Speeches, essays, songs and especially prints and lithographs began to glorify the domestic lives of public figures. These parlor portraits were not necessarily accurate portrayals. Some attempt was made to faithfully represent the male, whose face was usually well known from the newspapers. But the women and children were not always recognizable.

And the fat, overstuffed parlors! The artist usually furnished the setting from the attic of his imagination, lighting it with bulbous gas chandeliers; planting it with potted palms; enlivening it with ornate, square grand pianos; populating it with apple-cheeked boys, winsome girls and faithful and inspiring wives. In the case of presidents, past and present, a discreet representation of the Capitol dome often was shown in a window. The prints also presented a romantic, not realistic, view, making no references to illegitimacy (Grover Cleveland's child), insolvency (Ulysses S. Grant) incompatibility (Horace Greeley and his wife) impropriety (Adm. George Dewey) or insanity (Mary Todd Lincoln).

The famous Edward Savage family portrait of George Washington is the earliest in the show. The engraving actually was first issued in the 18th century, but its reissue in the 19th began a vogue. People bought the engravings or the newer and cheaper lithographs, framed them suitably, hung them in a place of importance and were thus edified by the presence in their own humbler homes of the Great Man and His Family.

In the 1798 print, Washington is still presented as an 18th-century national hero: set on a draped stage, equipped with globe, sword and the plans for the Federal City. But the Father of Our Country (and naught else) is also shown as a family man. Martha Washington and her two Custis grandchildren accompany the Great Man. And Billie Lee, Washington's highly regarded valet, is shown as a close member of the family.

Print curator Wendy Wick Reaves, who organized the show with great humor and sense of history, points out that among other influences on the print was the general 19th-century preoccupation with death. Mementoes mori were fashionable: memorial pictures, often made from locks of the deceased's hair; elaborate mourning costumes; essays and songs about the deaths of lovers and heroes. Assassinated presidents thus made ideal subjects.

Abraham Lincoln was the first popular 19th-century subject, especially in the wave of interest that followed his assassination. One of the more accurate prints (1865), by William Sartain, shows Lincoln's son Willie (who died in 1862) as a portrait on the wall, Lincoln's wife still in her prolonged mourning dress, as well as the couple's two living sons, Robert Todd and Tad. A sales broadside noted that a vase of flowers includes "the Roses of the North and the Small Magnolia, Sweet Clematis and Virginia Creeper, which bloom in profusion in the South; all wreathed in harmony, emblematical of the friendly feeling that should exist between the people of the North and South, in the great vase of the Union."

George B. McClellan, the Civil War general, was so well known that he was not even identified in the 1865 Currier and Ives lithograph "The Brave Wife," which shows his stoic spouse saying goodbye while the little boy with the overturned drum (a recurring symbol) cries.

Horace Greeley, who only visited his family once a week and had little money, is shown in tranquil and opulent domesticity in an 1872 litho by Otto Knirsch. Adm. George Dewey, who upset his admirers by deeding a house they had given him to his bride, is pictured by the Kurtz and Allison lithograph company in the parlor.

One of the last lithographs is of William McKinley with his wife, Ida Saxton McKinley, and his mother, Nancy Allison McKinley, in the foreground and his birthplace and his adult home (including the famous front porch on which he campaigned) tucked in at the top.

With the coming of Theodore Roosevelt, Reaves says, photographs in magazines showed the true likeness of people and parlors, and the private lives of public figures became private no more.

This charming show unfortunately has no catalogue, usually one of the great assets of a Portrait Gallery exhibit.