Question: Which church did George Washington serve as a vestry member for 24 years?

Answer: Christ Church in Alexandria, right? Wrong. Pohick Church in Lorton, Va.

Sunday, two days before the 251st anniversary of Washington's birth, many people will attend Christ Church and contemplate the hours the first president spent there. But Washington spent much more time at Pohick.

It's true Washington attended services at Christ Church when he stayed overnight in Alexandria, but his allegiance and heart were with a small Episcopal church that lies 10 miles south of Alexandria, off Rte. 1.

Today Pohick Church is one of the fastest growing churches of the Diocese of Virginia. Its congregation of 600 has almost doubled in the last five years.

Most parishioners don't seem to mind the lack of credit their church receives for its best-known member, but longtime church member George Bixby summarizes the frustration some feel: "Case in point: On the 250th anniversary of George Washington's birth, President Reagan attended Christ Church and Secretary of Defense Caspar Weinberger attended Pohick."

No one quite knows how the confusion first started, especially since the facts overwhelmingly show Pohick to be the church that George Washington built--literally.

Washington, George Mason and George William Fairfax all served as members of the building committee before the completion of Pohick Church in 1774.

The present Pohick Church is descended from an earlier chapel erected around 1700 that was rebuilt about 1730 as part of the redesignated Truro Parish. Located "above the Occoquan ferry," according to vestry minutes, the church was originally known as Occoquan Church, but by 1733 the Truro vestry book referred to it as Pohick Church.

It seems the redistricting of the parish lines in the 1760s, done for political reasons, is where the confusion between Christ Church and Pohick began.

The Rev. Albert Jones, rector of Pohick Church for 26 years until his retirement last May, explains the redistricting best:

"In the 1760s, a division of parish lines was made by the House of Burgesses. All the Washington holdings, including Mount Vernon, became included in Fairfax Parish, which meant one of the wealthiest men in the area became a citizen of Alexandria, bringing more money to Fairfax Parish, which included Christ Church.

"Fairfax Parish elected Washington to its vestry, but he never attended a vestry meeting. At the next meeting of the House of Burgesses they introduced legislation to again change the parish lines, and Mount Vernon was restored to Truro Parish and Washington was elected immediately to the vestry."

The Rev. William Sydnor, who was rector at Christ Church from 1959 to 1976 and is now retired and living in Alexandria, agrees: "George Washington wasn't on the vestry at Christ Church; that's a fable. But he frequently attended Christ Church. He was elected to the vestry but never served. It was strictly a paper exercise."

Washington officially served on Pohick's vestry from 1762 to 1784, following the footsteps of his father, Augustine, who was first elected to the vestry in 1735.

Pohick Church lies five miles south of Mount Vernon, Washington's estate, and five miles north of Gunston Hall, Mason's estate. Mason and Washington planned it that way after an amicable debate.

Originally the proposed site of Pohick was two miles north of Gunston Hall. When Washington got wind of the plan he immediately put a team of surveyors to work and presented a detailed site proposal to the congregation, persuading them to settle on the present site of the church.

Since colonial times, Pohick has survived being used as a stable and resting ground for both Union and Confederate troops during the Civil War. The structure was nearly gutted during the winter of 1862-63, and soon after the east wall was used for target practice. Stone door encasements still bear the marks of 19th century graffiti.

Today Pohick is undergoing a different sort of trauma: It is searching for a new rector.

A search committee was established last July to begin the lengthy, often emotional task. Since July it has met every Monday, and the Rev. Robert Blackington, the interim rector, predicts a new rector will be selected by Advent, or December.

In the last 10 years the Episcopal Church has changed the process by which a church selects a new rector. A congregation does a self-study, describing where it would like to be in the future, says Bishop Robert Hall, who heads the 200-church Diocese of Virginia.

"Then they try to match that profile with a rector for the church," Hall says. "If you rush the selection process too much they will draw up a profile and try to match Al Jones the former rector . There needs to be an emotional cooling-off period, if you will."

For Pohick the emotional cooling-off period was difficult, but also has brought a surprising sense of camaraderie among the parishioners.

"My main concern when I started as acting rector was to keep the ship on course. There was generally, throughout the congregation, grief when Mr. Jones left; you could feel it," says Blackington.

But the profile of Pohick Church, which will be published later this month, reflects a strong, wealthy membership. John Airail, senior warden of the vestry, points out the profile's most surprising facts:

* Pohick's membership and budget doubled in the last five years, with a budget of $200,000 for 1983.

* One-fourth of the congregation has five or more years of college education.

* More than half the parishioners earn $20,000 to $50,000 annually, and 23 percent earn $50,000 to $100,000 annually.

* Parishioners over age 65 make up 8 percent of the congregation, 34 percent of the congregation are students, 28 percent are under the age of 18.

Pohick's growth in the last 10 years springs mostly from the Springfield, Burke and Mount Vernon areas of Northern Virginia.

The affluence of many members and a workable budget weren't always the case for this country parish.

Its 40 acres are bordered by Lorton Reformatory, Rtes. 1 and I-95 to the west, Mason's Neck Wildlife Refuge and other park land to the southeast, and 10,000 acres of Fort Belvoir directly to the north. Needless to say the congregation has not always been cohesive.

"I can remember times when we would have 34 children in confirmation from 24 different schools," recalls Jones.

Pohick has always kept its history alive. For example, the congregation is currently having an "exchange of information" with Washington Parish Church in England, the 700-year-old church of the Washington family.

Blackington, explaining Pohick's successful marriage of the past and present, says, "The spirit of Christ is evident in all aspects of parish life; it's our strongest point. We all appreciate our history and like to think of it as a living part of the church."