How can I make my vertical labels fit within my plotting window

hist(vector, axes = FALSE, breaks = chartBreaks)
axis(1, at = tickMarks, labels = eventTypes, las = 2, tick = FALSE)

set.seed(123)
vec <- sample(1:9, 100, replace = TRUE)
vec <- factor(vec, labels = paste("My long event name", 1:9))

## lots of extra space in the margin for side 1
op <- par(mar = c(10,4,4,2) + 0.1)
barplot(table(vec), las = 2)
par(op) ## reset

dotchart(table(vec))

par(mar=c(5,3,1,1))   # extra large bottom margin
hist(vector, axes = FALSE, breaks = chartBreaks)
axis(1, at = tickMarks, labels = eventTypes, las = 2, tick = FALSE)