The following is an etymology of expressions commonly found in Georgian and Regency fiction:

ahem - by 1765

balderdash – from 1660
beastly – from 1850
bedamned -- 20th C.

begad - by 1600

blast – from 1850
blasted – (bloody) from 1740
bleater -- 17th - early 19th C.
bleating (bloody) -- 17th - early 19th C.
bleeding – from 1857
blimey – late 19th C.
blighter – 20th C.

blister it -- 1840
bloody (very) -- mid 17th to 18th C.

bloody (damned) - by 1670
botheration – by 1835

bravo - by 1765

brava - by 1805

bugger (chap or fellow) -- from 1719
bugger all/it -- from 1880
by (Saint) George – from 1731
by gum – from 1825
by Jove – from 1570
by the bye – from 18th C.
capital – from 1760
cheeky – from 1857
cheerio – ca. 1910
confound it – 19th to 20th C.
cripes – late 19th C.
daft – from mid. 19th C.
damnable – from 16th C.
damnation – from 1750

dang - by 1790
daresay – by 1350
darling (deriv. of Middle English derling, and Old English deorling) --

             before 12th C. in use by 1510

darn - by 1785

darned - by 1815

dear -- by 1675

dearling – (see darling)
dash it all – from 1870
dash my wig – from 1810
dem (damn) -- from late 17th C.
demme (damn me) -- from 1753
deuced (damned) -- from 1774
devil a bit – after 1850
devilish – from 17th C.
devil of a (time, mess, etc...) – from 1836
devil’s own luck – 19th to 20th C.
devil take it – from 16th C.
devil to pay – 15th to 20th C.

dickens (What the dickens?) - by 1600
drat – by 1815
egad -- by 1675

eureka - by 1570

excelsior - by 1780
fancy that – from 1834

fiddle-de-dee - by 1785

fiddle faddle – 18th to 20th C.
fiddlesticks – 17th to 20th C.
frigging (exceedingly) -- from 1820
frightfully – from 1830

fudge - by 1770

fun (joke) – by 1835
fustian (bombast) -- from late 18th C.
gads -- from C. 17th C.

gadzooks -- by 1655

gammon (nonsense) – from 1825
ghastly – from 1860

glory be - by 1820

goody - by 1800

golly - by 1775
good gracious – 18th to 20th C.
goodness – from mid 19th C.
good show – from 1925

gosh - by 1760

go to the devil – from late 18th C.
gracious – 18th to 20th C.
gracious me – 19th to 20th C.
hells bells – from late 19th C.
hellfire -- before 1760
honey – 19th C.
humbug – from 1751
hussy – from 1550

hurrah -- by 1690

huzzah -- by 1595

I’ll be bound – from 1530
I say – from late 19th C.
Jupiter - 17-20th C.
just so – ?
la – 16th to 20th C.
lawks – (low coll.) from 1765

lo and behold -- by 1810
Lud – ca 1720-1850
mind (note what I say) -- from 1806

Oh - by 1175

oh-oh -- by 1730
outside of enough – from around 1887
pah -- from 1600
piffle – from 1890
pooh -- from 1600

pshaw -- by 1675

quite – from mid 1890s
right – from 1837
right you are – from 1865
right-o – 20th C.
ring a peal – 18th to mid 19th C
rot it – 17th to 18th C.
rotter – from 1894
ruddy (bloody) – from 10th C.
shag – late 18th C.
sirrah – from 16th C.
smashing – by 1850
sodding – late 19th C.
sod off – 20th C

son of a bitch (interjection) by 1675

son of a bitch (noun) by 1710

sweetheart – deriv. of Middle English swete herte from 14th C.
sweeting – archaic form of sweetheart. from 13th C.

tallyho - by 1770

tosh - nonsense b. 1530

What (how) the devil – from 17th C.

zooks - by 1635

zounds - by 1600

Resources:
A Dictionary of Slang and Unconventional English, by Eric Partridge, MacMillan Company, 1970
English Through the Ages, by William Brohaugh, Writer’s Digest Books, 1998
Merriam Webster’s Collegiate Dictionary, Tenth Edition, 1993

ain’t – in use by 1780

‘cause (because) in use by 1450

can’t – by 1655

couldn’t – by 1650

don’t – by 1640

e’en (even) – by 1300

e’er (ever) – by 1300

‘em (them) – by 1100

I’d – by 1655

I’ll – by 1570

I’m – by 1595

I’ve – by 1745

it’s – by 1625

ma’am – by 1670

mustn’t – by 1745

ne’er (never) – by 1300

o’ (of) – by 1300

o’clock – by 1720

shan’t – by 1655

she’d – by 1745

she’ll – by 1595

shouldn’t – by 1850

‘tain’t – by 1820

they’d – by 1680

they’ll – by 1615

they’re – by 1595

they’ve – by 1615

tone (the one) – by 1350

tother (the other) – by 1350

‘twas – by 1590

‘tween – by 1300

‘twere – by 1590

‘twixt – by 1350

wasn’t – by 1850

we’d – by 1605

we’ll – by 1580

we’ve – by 1745

who’d – by 1640

won’t – by 1655

wouldn’t – by 1830

you’d – by 1605

you’ll – by 1595

you’re – by 1595

you’ve – by 1695