The discrepancies shown regarding the birthplaces of his parents in the censuses are typical of an orphaned child.

Merdick, Bertha, and Lollie were killed or mortally injured in the same auto accident.

1.  Marriage Record:

2.  1910 U.S. Census Every-Name-Index/Images (online at Ancestry.com):  Unfortunately, the page image online at Ancestry is unreadable.  I'm depending on their the index, which tells us that Luther ANDERSON (æ 10, b. MI) is living in Sault St. Marie, Chippewa Co., MI (p. 223B), as an adoped child of August ANDERSON (æ 36, b. Finland) & Mary (æ 37, b. Finland).  Everyone's parents were born in Finland.  We cannot be certain this is our subject, but I scanned all the 9/10-year-old male ANDERSONs in Michigan, and he appears most likely to be our subject.

3.  1920 U.S. Census Every-Name-Index/Images (online at Ancestry.com):  Luther ANDERSON (æ 17, b. MI) is living in Ironwood City, Gogebic Co., MI (p. 168A), as a foster child with Anna L. STENSTROM (æ 66, b. Sweden).  Both show parents born in Sweden.  Without further coroboration, we cannot be certain this is our subject, but I didn't find anyone closer.

4.  1930 U.S. Census Every-Name-Index/Images (online at Ancestry.com, Image #11 of 19):  2nd St. James Goose Creek Twp., Berkeley Co., SC, Roll 2188, p. 171A, SN 6A, ED 8-13, SD 11, enumerated 8 Apr 1930, official enumeration date 1 Apr 1930 (extracted by Diana Gale Matthiesen):

1930:  for an explanation of the column headings, please see What the Numbers in the Federal Census Mean (missing columns contained no data).

3

4

5

6

7

10

11

12

13

14

15

16

17

18

19

20

24

25

26

27

28

30

32

111

111

Anderson Luther

Head

O

Y

M

W

29

M

21

N

Y

MI

MI

MI

Y

Farmer

General Farm

O

Y

N

46

________ Bertha

Wife

X

F

W

27

M

19

N

Y

MI

MI

MI

Y

None

________ John

Son

X

M

W

7

S

N

MI

MI

MI

None

________ Charlotte

Dau

X

F

W

5

S

N

MI

MI

MI

None

5b.  1940 U.S. Census Every-Name-Index/Images (online at Ancestry.com, Image #1 of 22):  Institution Campus, State Training School (for Mental Defectives), Jacks Twp., Laurens Co., SC, Roll T627_3821, p. 276A, Line 13, SN 1A, SD 4, ED 30-22, enumerated 22 Apr 1940, official enumeration date 1 Apr 1940 (extracted by Diana Gale Matthiesen):

1940:  for an explanation of the column headings, please see What the Numbers in the Federal Census Mean.
HOUSEHOLD				NAME	RELATION		PERSONAL				EDUCATION			BIRTHPLACE		CIT	RESIDENCE in 1935					EMPLOYMENT STATUS															FS
3	4	5	6	7	8		9	10	11	12	13	14		15		16	17	18	19	20		21	22	23	24	25		26	27	28	29	30		31	32	33	34
			N	Anderson, Charlotte	Inmate		F	W	15	S	N	0		Michigan			R	Horry	South Carolina	Y		Inst

6b.  South Carolina Deaths, 1915-1943 (online at FamilySearch.org):

6c.  South Carolina Deaths, 1915-1943 (online at FamilySearch.org):  why no certificate for Lollie?

7a.  Anon.  Friday, 29 Mar 1940.  "Fourth Death Occurs Today."  Evening Post (Charleston, SC), p. 2 (online at GenealogyBank.com):

FOURTH DEATH OCCURS TODAY Mr. and Mrs. M. L. Anderson and Child, of Givhans, Lose Lives COLLISION OCCURS NEAR THE ANTLERS Driver of Auto Succumbs This Afternoon at Summerville    Frank Saunders, driver of the automobile which collided with an oil truck at the Antlers, about 13 miles from Charleston, yesterday afternoon, bringing death to three occupants of the car, died this afternoon a few minutes before 3 o'clock.    The three fatally injured in the mishap Thursday were Mr. and Mrs. M. L. Anderson and their daughter, Lila Mae, 10, all of Givhans.  They were en route home after a visit in Charleston.    The parents were killed instantly in the collision while the little girl died 10 o'clock last night at the Dorchester county hospital, in Summerville, where she was taken, along with Saunders.  The Andersons were identified by Sheriff Herbert H. Jessen.    H. S. Oliver, of Columbia, driver of the oil truck, was uninjured and following an investigation was released on this own recognizance for appearance whenever summoned.  The truck was slightly damaged.    Deputy Coroner George A. Brandes and County Policemen Percy W. Hardwicke and J. Henry Moessner reported that the truck was proceeding toward Charleston when is collided with the automobile which had just left the double lane highway and was entering the highway to Summerville.    The officers said the automobile was knocked beyond a ditch on the left side of the road and was completely demolished.  Mr. and Mrs. Anderson were sitting in the rear seat, with Saunders and little girl in the front.  [Skipping the unnecessary details of their fatal injuries.] Funerals May be Tomorrow    Funeral plans for the Andersons were undetermined today, it was said at J. Henry Stuhr, Inc., where the bodies have been prepared, because the only survivor of the immediate family, a son 16 years old, said he wished first to consult with relatives.  The boy an enrollee of a CCC camp, arrived in the city shortly after noon and after viewing the remains of his parents and sister left for Dorchester county, where he hoped to get the assistance of some of his relatives.

7b.  Anon.  Saturday, 30 Mar 1940.  "Funeral Rites for Andersons."  Evening Post (Charleston, SC), p. 2 (online at GenealogyBank.com):

FUNERAL RITES FOR ANDERSONS Three Victims of Accident Laid to Rest; No Inquest Planned    Funeral services were held this morning at the Pinegrove Baptist church, near Summerville for Mr. and Mrs. M. L. Anderson and their ten-year-old daughter, who were fatally injured in a traffic accident near the Antlers Thursday afternoon.  J. Henry Stuhr, Inc., had charge of the arrangements.    The plans for the funeral were made by a sixteen- year- old boy, the son of Mr. and Mrs. Anderson, the only survivor of the family.    Funeral plans were being made today for Frank Saunders, 54, driver of the Anderson car.  He died yesterday afternoon in the Dorchester County hospital at summerville from injuries received when the automobile crashed with an oil truck driven by H. S. Oliver, of Columbia.    It was said at Coroner John P. DeVeaux's office today that an inquest was not necessary now that Saunders has passed away.

Apparently, the crash was blamed on Saunders.

.  Find-a-Grave: Entries (online at findagrave.com):

Name	Merdick L. Anderson	Bertha R. Anderson	Lollie M. Anderson
Birth	1898	1894	1934
Death	Mar. 28, 1940	1940	1940
Burial	Pine Grove Baptist Church Cemetery No. 2 Givhans, Dorchester County, South Carolina
Inscription	ANDERSON MERDICK L. 1898 — 1940 LOLLIE M. 1934 — 1940 BERTHA R. 1894 — 1940
Father			Merdick L. Anderson
Mother			Bertha R. Anderson
Spouse	Bertha R. Anderson	Merdick L. Anderson
Children	Lollie M. Anderson	Lollie M. Anderson
Memorial #	58876334	58877965	58876545

.  Messages posted to the Michigan [Unknown County] Location Board (online at Ancestry.com).